It has been reported that systemic hypoxia aggravates the development of atherosclerotic lesions and systemic hyperoxia regresses it, but the mechanisms are not known. The aim of this report is to investigate, in in-vivo, the effects of hypoxic inhalation or hyperoxic inhalation on the rabbits with dietary hypexcholesterolemia or with spontaneous hyperlipidemia from birth for 8 weeks, and to.investigate, in in-vitro, the effects of 2% O₂ on the cells which are cultured in the EME medium supplemented with 20% hyperlipidemic rabbits serum or 20% normolipidemic rabbits serum. The following results were obtained.
1) From in-vivo experiments, atherosclerotic lesions were accelerated by the inhalation of 10% oxygen (hypoxic) and regressed by the inhalation of 40% oxygen (hyperoxic).
2) Lipoperoxide levels in plasma were increased by the oxygen inhalation, but the increments were much higher in hypoxic condition than in hyperoxic condition.
3) There were significant correlation between the %-aortic lesions and the lipoperoxide contents ln aorta.
4) The contents of hydroxyprolin in aorta, precursor of collagen, were much higher in hypoxicgroup than hyperoxic group.
5) From in-vitro experiments, esterified cholesterol contents in the cells under the hypoxic condition were raised 2-3 fold as much as those in control, when the cells were incubated in the medium supplemented with hyperlipidemic glasma.
6) Lipoperoxide contents in the cell were increased under the hypoxic condition and reversed by the addition of antioxidant, a-tocopherol, under the identical condition.
From these results, we conclude that the development of atherosclerotic lesions is aggravated by the accumulation of esterified cholesterol and lipoperoxide in the cells surrounded by the hyperlipidemia under the hypoxic condition.

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Normal male rabbits of which ear lobes had been installed a transparent round-table chamber for vital-microscopic observation of the cutaneous microcirculation were fed a cholesterol-supple-mented (1.5%, w/w) diet for a period of 12 weeks. A marked lipid accumulation in the wall of aorta was noticed at the end of the cholesterol loading during which an enormous elevation of LDL-cholesterol levels in plasma was observed concurrently with anemic findings on macrocirculatory blood and changes in intravascular behaviors of cellular components of microcirculatory blood. The anemic findings included decreases in erythrocyte counts, hematocrit values, and hemoglobin concentrations and increases in erythrocyte sedimentation rates as well as in carboxyhemoglobin concentrations. The intramicrovascular changes included enhancement of adhesiveness of circulating leukocytes showing thrombus-like formations on the wall of vessels and/or obstructions of vascular lumens and abnormal erythrocyte aggregation such as rouleau formation and sludging. Both the macrocirculatory and microcirculatory changes, in combination with the elevated LDL-cholesterol in blood, appeared to suggest to facilitate the atherogenic process through an increased permeability of the arterial endothelium resulted from the systemic anemia and local hypoxia due to the disturbance of oxygen supply of erythrocytes caused by the leukocyte adhesion to the wall of vessels. Although cigarette smoke inhalation alone (repeated two times a day in a dose of 5mm length of cigarette burnt for one smoking session) did not induce any appreciable changes in lipids in the aorta as well as in the biochemical measurements, during the same experimental period, inhalations of filtered (with glass fiber Cambridge filter) or non-filtered smoke concurrent with cholesterol feeding induced more or less alteration of the aortic accumulation of cholesterol and the macro- and microcirculatory findings on blood. Particularly the gase phase substances or carbon monoxide in cigarette smoke appeared to have exacerbating influences on the dietary atherogenic process.

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We observed the effects of lanthanum (La³⁺, an inorganic Ca²⁺-channel blocker) on experimental atherosclerosis in rabbits fed on cholesterol.
16 male Japanese white rabbits weighing 2.1-2.7kg were fed on a 1% cholesterol diet for two weeks, and then divided into two groups so as not to make statistical differences of the serum total cholesterol levels between the two groups. One group was fed on a 1% cholesterol diet plus 0.12% LaCl₃ (40mg/kg/day), and the other (control) group was fed on a 1% cholesterol diet only. At the end of the 14 week period, all animals were killed and autopsied.
There was no difference in serum total cholesterol between the La³⁺-treated rabbits and the control rabbits through the experimental period. Serum triglyceride, phospholipid, HDL-cholesterol, total protein, and albumin levels were also similar in both groups through the study period. LaCl₃ was well tolerated and the increases of body weight did not differ significantly between the groups. LaCl₃ had no effects on arterial pressure. Serum calcium and inorganic phosphorus were similar in both groups through the study. Serum calcium increased after six weeks and then returned to normal. Serum inorganic phosphorus increased after two weeks but decreased at six weeks and then returned to normal level. 1% Cholesterol diet itself might have influence on the metabolism of calcium and inorganic phosphorus. Platelet aggregability measured by screen filtration pressure method was inhibited significantly at the end of the study in the La³⁺-treated rabbits. La³⁺ by itself had no significant effects on platelet aggregation in vitro.
Aortic lesions stainable with Sudan II covered 36.3±8.6% of the intimal surface in the control rabbits, and 25.4±5.5% in the La³⁺-treated rabbits. Histopathologically, intimal foam cell layer was thicker in the control rabbits than in the La³⁺-treated rabbits. Relative plaque deposition of intramural coronary arteries was similar in both groups. Fatty degeneration of the liver was suppressed in the La³⁺-treated rabbits.
Although our results were not so remarkable as those of D. M. Kramsch et al., we are sure that La³⁺ suppressed experimental atherosclerosis in rabbits without reducing hypercholesterolemia. Inhibitory effects of other Ca²⁺-channel blockers on experimental atherosclerosis and the mechanisms of these drugs are currently being studied by us.

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To elucidate the repairing process and the pathological significance of a minute endothelial injury in the development of arteriosclerosis, minute endothelial desquamation areas were produced by applying a weak electric current to the endothelium in the central segments of the rabbit common carotid arteries. And the endothelial repairing process and the effect of hypercholesterolemia on the process were studied by pathomorphologic methods including scanning electron microscopy. The following results were obtained.
1. By the effect of electric current, a small area of endothelium was desquamated (lesion A, after 1 sec injury; 0.84×0.14mm, lesion B, after 5 sec injury: 1.68×0.32mm), and the Evans blue injected intravenously was insudated into that area. But no large thrombus was formed.
2. In both groups with normo- and hypercholesterolemia, denuded areas were rapidly reendothelialized by 24 hours (lesion A) or 3 days (lesion B).
3. In the group fed with the normal diet, the insudation of Evans blue at the injured area ceased coincidentally with reedndothelialization, but in the group fed with the cholesterol diet, the insudation continued for 9 weeks after the electric injury.
4. In the group fed with the normal diet, the injured areas did not formed any arteriosclerotic lesions by 9 weeks after the injury. In the group fed with the cholesterol diet, however marked arteriosclerotic lesions were developed in the injured areas.
5. Three weeks after the injury in the group fed with the cholesterol diet, foam cells were seen on the luminal surface. These cells might be considered to be foam cells released from the thickened intima into the arterial lumen through the newly opened interendothelial junctions or the portions of new endothelial cell loss.
The present study suggested that minute endothelial desqamation which is reendothelialized in a short period of time under a normolilpidemic condition, is an important facter in development of atherosclerosis under hypercholesterolemia.

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Blue area (Evans blue accumulated area) and white area (Evans blue non-accumulated area) in the aortic arch of rabbits were studied about differences of permeability from the point of view of intimal structure. Permeability of both areas in hypercholesterolemic rabbits was also observed.
Blue area showed an increased permeability, compared with white area in normal rabbits. Though endothelial cells and their junctions were not structurally different in blue and white areas of normal rabbits aortic arch, disruption or disappearance of basement membrane, widening of subendothelial space, frequent existence of modified smooth muscle cells and fenestration of internal elastic lamina were seen in the blue area. Though it was not determine whether this phenomenon is primary or secondary, its was suggested that disappearance of basement membrane in blue area plays an important role of intimal permeability.
The permeability was markedly accelerated in blue area of hypercholesterolemic rabbits. Some foamy cells appeared at the subendothelial space neighbored to the blue area in on week cholesterol fed rabbits and theirafter, in addition to the increase of modified smooth muscle cells, foamy cells also appeared in the blue areas of two weeks cholesterol fed rabbits.
It was considered that plasma constituents and cholesterol permeated into subendothelial space of blue area transversely flow in the aortic intima and are accumulated in surrounding area of blue area. As a result, it was suggested that fatty lesions are formed in area corresponded with blue area.

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We have developed a new method of aortic pulse wave velocity measurement (PWV) as a means of evaluating experimental arteriosclerosis and established a practical noninvasive procedure for sequential determination of the progress of arteriosclerosis. Further, we have also established a procedure for quantitative, histochemical determination of the main aortic wall constituents, such as elastin (EB), collagen (CL), acid mucopolyssacharides (AMPS), glycoprotein (GP), smooth muscle (SM) and deoxyribonucleic acid (DNA). In this investigation we determined changes in aortic pulse wave velocity in groups of healthy and arteriosclerotic rabbits and quantitatively determined the six arterial wall constituents to clarify the diminished function and degeneration of sclerosed arteries in the rabbit.
Materials and Methods
The animals used in this investigation consisted of 5 healthy Japanese native white rabbits at 38 months of age and 5 arteriosclerotic ones. An artificial carotid arterial loop was produced in all the 10 rabbits so that blood pressure and pulse wave velocity measurements might be obtained. Experimental arteriosclerosis was induced through combination of three methods; hypoxia (induded by N₂ gas inhalation), tissue impairment (by intramuscular administration of epinephrine), and vasovasorum occlusion and intimal thickening (by oral administration of cholesterol). Pulse wave velocity and blood pressure measurements were obtained twice weekly, and both healthy and diseased groups were sacrificed 22 weeks after initiation on study and specimens of arterial wall constituents were obtained from isolated aortas. The relationships between kinds of stainning and absorption wavelengths were as indicated below: Weigert for EL; 590nm, van Gieson for CL; 563nm, Alcian Blue for AMPS; 608nm, PAS for GP; 565nm, Azocarmin G for SM; 545nm, and Schiff for DNA; 512 and 570nm. Quantitative determinations were carried out, using MSP and scanning each tissue specimen at 20 to 30 sites with a set of a 10-power object lens, a 10-power condenser and a pinhole turret No. 6. The levels of arterial wall constituents were expressed in absorbance.
Results
1. The systolic pressure for the healthy rabbits ranged from 110 to 140mmHg and the diastolic pressure, from 60 to 80mmHg, as is exactly the case with adult humans. Both systolic and diastolic blood pressures in the arteriosclerotic rabbits were higher by 10% than in the healthy rabbits.
2. Initial values of PWV obtained in both groups ranged from 7.5 to 8.0m/sec. However, whereas PWV values remained unchanged in the healthy group, the arteriosclerotic group had a gradual increase, and at 4 weeks the difference was statistically significant (p<0.05 to 0.01). Ultimately at 22 weeks (end of the study) the mean PWV value stood at 7.58±0.2m/sec for the healthy group, while it was 8.76±0.43m/sec (p<0.001) for the arteriosclerotic group.
3. The differences in the levels of six arterial wall constituents between the two groups were as indicated below.
4. To clarify the implications of changes in the levels of six constituents, the rate of contribution to sclerosis was determined for each of the constituents. The rate of contribution for the first principal component by multivariate statistical analysis was 62.27%. DNA, SM, CL and EL were decreased by 0.889, 0.832, 0.819 and 0.812 respectively, while GP and AMPS were increased by 0.824 and 0.496 respectively. Accordingly, the first principal component can be considered important as a sclerosis-promoting factor. The rate of contribution for the second principal component was 14.47%. This value is not high enough to implicate the second principal component as a positive sclerosis-promoting factor, but the total contribution of the first and second principal components by was as high as 77.74%.
5. Further, the linear equation of estimation and coefficient of correlation derived from the PWV values and scores

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By aplying a non-traumatic technique originally developed for measuring the viscoelastic property of the arterial system in the rabbit forearm, we tried to follow up the progressive and regressive responses of the atherosclerotic process in the hyperlipedemic rabbits. The visco-elastic property of the arterial system was measured with a photoelectric approach using a light emitting diode and a phototransistor directly attached on the skin in the opposing position of the forearm and a cuff surrounding them. When the tissue was compressed by linearly elevating the cuff pressure, the consequent reduction of the blood volume in the tissue was detected by the increased intensity of the transmitted, infrared light proportional to the transistor output. From such DC components combined with the AC components due to the arterial pressure pulsation, we calculated the relative pressure-volume relationship of the whole arterial tree in the tissue under the cuff which allowed us to evaluate the volume elastic moduli (Ev) for varied transmural pressures. In 9 rabbits feeded with 1% cholesterol diet, the measurement of the forearm arterial elasticity was repeated every two or four weeks for each animal. In 6 rabbits, gradual increases in Ev values became evident 6 to 9 weeks after the onset of the cholesterol diet, implying the delayed atherosclerotic change in the elastic property. In 2 animals, the regressive process was observed by shifting the cholesterol diet so far loaded over 6 months to the normal one. The initial distinct decreases in Ev values were observed 6 to 8 weeks after the resumption of the normal diet and in 13 to 20 weeks, Ev values reached very close levels to the normal control curve.

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Enzyme activities, which regulate the lipid metabolism in arterial wall as previously reported, were determined in atherosclerotic rat or rabbit induced by high cholesterol diet administration. Lysosomal or microsomal enzyme activities were increased, except for choline-phosphotransferase, in hypercholesterolemia compared with normolipidemia. However, these enzyme activities were decreased in atherosclerotic arterial wall induced by combination of hypercholesterolemia and Vitamin D₂ administration compared with hypercholesterolemia.
Remarkable atheromatous lesions were observed in hypercholesterolemic rabbit arterial wall induced by high cholesterol diet. In that condition, enzyme activities as described above were induced in atheromatous arterial wall compared with nonatheromatous arterial wall.

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Experimental atherosclerosis was induced in rats by administering Vit. D₂ and atherogenic diet in order to examine any abnormal metabolisms of connective tissues, which were supposed to be one of the atherosclerotic factors, and in order to compare with those changes in spontaneously aged rats (at 4 weeks, 6 months and 12 months of age). Antiatherosclerotic effects of the pancreatic elastase preparation (450 ELU/rat/day) were examined in parallel with the induction experiment by administering the enzyme i.m. during the course of the atherosclerotic induction.
It was found as the result that 1) in the experimentally induced atherosclerotic rats, amounts of such arterial connective tissues as elastin and collagen were tend to be decreased, which was different from the spontaneous ageing process, and the degree of the reduction in amount of connective tissues was dependent on the dose of administered Vit. D₂.
Specific radioactivity of ³H-Hyp in the experimentally induced atherosclerotic artery, after administrating 20μCi/rat/day of ³H-Pro in vivo for 7 days, was examined, and it was found that the incorporation of the radioactivity was significantly higher in the experimentally induced atherosclerotic artery than in the control one, which might reflect the fact that the catabolism of the connective tissue was more stimulated. On the other hand, specific radioactivity of ³H-Hyp in collagen was almost normalized to the level of control by the administration of elastase preparation. 2) The tissue fractions, to which the cholesterol was bound, were examined in the arteries of man and experimental animals. Most cholesterol was found in elastin fraction (elastin-cholesterol) in the atherosclerotic human aortic artery (aortic arch and thoracic artery) and experimentally induced atherosclerotic rats. The elastin-cholesterol was more abundant in such experimentally induced atherosclerotic artery than in the control one, but no such tendency was shown by spontaneous ageing. Pancreatic elastase preparation lowered the elastin-cholesterol level, probably because of alteration of metabolic turnover in aortic elastin, and thus abnormal metabolism might have been improved. 3) The components of the lysine-derived cross-links structure (isodesmosine, desmosine, merodesmosine and lysinonorleucine) in the elastin fraction, in which the elastin-cholesterol was found, were examined in comparison with lysine content, and these components were reduced in amount as expressed by the ratio to lysine. No such change was shown by ageing. Administration of elastase preparation normalized merodesmosine level to that of the control.
Abnormal metabolic changes were shown by the connective tissues (collagen and elastin) in the atherosclerotic artery, and pancreatic elastase preparation normalized these abnormalities to some extent. It may be posturated that abnormal metabolism of the arterial connective tissue could be one of the causative factors of atherosclerosis.

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High density lipoproteins are known to have a function to remove cholesterol from the peripheral tissues. To study the mechanism of cholesterol removal by HDL, and to multiply the function of HDL, modified HDL was prepared with polyenphosphatidylcholine vesicles (soya bean lecithin=dilinoleoyl phosphatidylchone>60%, deoxycholic acid (250mg/500mg PPC) and their functions were studied. PPC vesicle itself increased the release of [³H] cholesterol from [³H] cholesterolladen peritoneal macrophages of rats and was much more efficient than dipalmitoyl phosphatidylcholine vesicles. Apolipoprotein AT, CI and CIII alone did not enhance the release of [³H] cholesterol, but in the presence of PPC vesicles or DPPC vesicles, these Apolipoproteins augumented the releases of [³H] cholesterol from macrophages. Incubation of PPC vesicle with HDL formed new complexes. These complexes eluted at density from 1.14 to 1.28 in zonal ultracentrifugation and were poor in apoprotein AI and AII (2.5% or 25% of that in native HDL) and rich in phospholipid. The addition of modified HDL to macrophages which were preincubated with [³H] cholesterol or [³H] cholesterol oleate-labeled acetylated low density lipoprotein, increased the release of [³H] cholesterol from the cells. Their releasing activities were greater than native HDL, when the releasing activity was expressed as a function per protein concentration of HDL or modified HDL. These results suggest that removal of [³H] cholesterol from the macrophages was multiplied by modifying HDL with PPC vesicles.

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We measured the levels of HDL₂ and HDL₃ cholesterol in patients with liver cirrhosis or chronic hepatitis, and in normal control subjects by high performance liquid chromatography to clarify the metabolic mechanism of HDL subfractions. Twenty three patients with liver cirrhosis and thirteen patients with chronic hepatitis, and twenty two normal control subjects were studied. The diagnosis in the patients with liver cirrhosis or chronic hepatitis was based on liver biopsy, laparoscopy, and laboratory tests.
The values of HDL, HDL₂, and HDL₃ cholesterol were compared between male patients with liver deseases (liver cirrhosis and chronic hepatitis) and normal male controls. The values of obesity index and triglyceride were matched between the patients with liver cirrhosis and the normal controls. There was no significant difference in HDL cholesterol levels between the patients with liver cirrhosis and the normal controls. However in liver cirrhosis there was a decrease in HDL₃ cholesterol and a increase in HDL₂ cholesterol as compared with normal subjects (p<0.001, Fig. 1).
Table 1 and Table 2 show the correlation of HDL subfractions with liver function tests in thirty-six patients with liver diseases (liver cirrhosis and chronic hepatitis). We found a positive correlation of HDL₃-cholesterol with serum albumin and choline esterase values, and a negative correlation of HDL₃ cholesterol with ICG test, serum alkaline phosphatase, and serum total bilirubin values. Furthermore we found a positive correlation of HDL₂ cholesterol with ICG test, serum alkaline phosphatase, and serum total bilirubin values, and a negative correlation of HDL₂ cholesterol with serum albumin and choline esterase values.
The decrease of HDL₃ cholesterol in liver cirrhosis and the positive correlation of HDL₃ cholesterol with other indicators of hepatic protein synthesis (albumin and choline esterase) suggest that HDL₃ are secreted from the liver. The increase of HDL₂ cholesterol in liver cirrhosis and the positive correlation with ICG test, serum alkaline phosphatase, and total bilirubin values indicate the possibility that HDL₂ may be taken up and degraded in the liver.

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The difference in HDL-lipid constituents were examined between hepatic vein and femoral artery. in HDL, HDL₂ and HDL₃ most pronounced difference was found in triglyceride concentration which was significantly higher in femoral artery as compared to hepatic vein. Cholesterol and phospholipid concentration of HDL₂ alone but not of HDL₃ was also significantly higher in femoral artery than hepatic vein. Concentration of Apo A-I and A-II, on the other hand, remained unaltered in the blood circulation. These results in combination with the result that significant decrease of triglycerides of VLDL and LDL fraction (d=1.006-1.063) was observed in femoral artery as compared to hepatic artery, suggest that the accumulation of triglycerides in HDL is due to their transfer from other triglyceride-rich lipoprotein and accumulation of HDL 2b occurs in the blood stream from hepatic vein to femoral artery.

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The present study was to investigate the sialylation of apolipoprotein CIII (apo CIII) in very low density lipoproteins (VLDL) and its effects on lipid and lipoprotein metabolism in diabetes mellitus.
The composition of apo C subgroup in VLDL has been determined by polyacrylamide isoelectric focusing and scanning densitometry. As apo CIII₀ contains no sialic acid, apo CIII₁ one sialic acid and CIII₂ two sialic acid as their molecular components, the extent of sialylation of apo CIII was characterized by (apo CIII₁+apo CIII₂)/apo CIII₀, expressed as VLDL apo CIII sialylation index.
This index was correlated negatively to plasma triglyceride and LDL cholesterol and positively to HDL cholesterol and showed strong correlation (p<0.02) to atherogenic index, (Plasma cholesterol-HDL cholesterol)/HDL cholesterol.
VLDL apo CIII sialylation index was lower in oral hypoglycemic drug group than in diet and insulin therapy group, and was significantly low in type IV hyperlipidemic diabetics compared with in normolipidemic diabetics. This index was also significantly low in poor controled diabetics, whose hemoglobin A_I were above 10%, however, this index showed no correlation to hemoglobin A_I value.
On heparin administration (N=19), VLDL apo CIII Sialylation index increased signicantly, 5.30±2.81 to 6.44±2.94 (p<0.05) and changes in VLDL triglyceride concentration by heparin administration showed negative correlation to the value of VLDL apo CIII sialylation index of the sample before heparin administration. These two results revealed the extent of sialylation of apo CIII carried on VLDL may influence the lypolysis of VLDL.
Preliminary study of VLDL subfractionation by Geon-Pevicon electrophoresis also showed the extent of sialylation of apo CIII in VLDL presumably affects the charge of VLDL particle and its electromobility in electrophoresis.

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Serum lipoproteins and apolipoproteins in VLDL and HDL from SHR aged 40 weeks were analyzed by ultracentrifugation and isoelectrofocusing, and compared with those from Wistar Kyoto rat (WKR) with the same ages. These results are summarized as follows;
(1) Concentrations of every serum lipids from SHR were higher than those from WKR except HDLC. Serum TG of SHR was 2.5 times higher than that of WKR.
(2) Concentrations of VLDL and LDL from SHR were elevated when compared with those from WKR, especially the elevation of VLDL was remarkably. As no significant difference was found between HDL from both groups, the percentage of VLDL to total lipoproteins increased and that of HDL decreased in SHR.
(3) The increased percentage of TG and the decreased PL were observed in VLDL fraction from SHR. In LDL and HDL fractions of this rat, the percentages of CH and PL increased, and those of apoproteins and TG decreased.
(4) Although apo C_II/C_III ratio and apo C_III composition in VLDL were not significantly different between both groups, the ratio of apo E protein decreased in VLDL of SHR. There were the reduction of apo A protein ratio and the increases of apo E and C protein ratios in HDL fraction. The apo E/C ratio decreased both in VLDL and HDL, which might influence the interaction between serum lipoproteins and liver, whether it was induced primarily or secondarily.

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The concentrations of serum apolipoprotein A (M-Partigen-Apolipoprotein A, Behringwerke), A-I and A-II (Daiichi pure) were determined in 27 normal and hyperlipidemic subjects by the commercially developed SRID method. Apo A concentration was higher than sum of apo A-I and A-II concentrations, and the apo A/apo A-I+A-II ratio was 1.29±0.02. Apo A correlated with apo A-I+A-II (r=0.98). The same results were obtained even though specially prepared standard serum for each methods were determined by the different method. These data suggested that the differences between apo A and apo A-I+A-II concentrations which observed in the human serum were induced by the differences of indicated values of standard serum in each method.
Whole serum formed single precipitin arc with a migration similar to HDL on crossed immunoelectrophoresis with anti apo A (anti human α-lipoprotein) serum. Delipidated HDL formed precipitin arcs of apo A-I and A-II with mixture of anti apo A-I and anti apo A-II serum. Delipidated HDL formed single precipitin arc with anti apo A serum on immunoelectrophoresis, but not formed on rocket immunoelectrophoresis and Ouchterlony method. Delipidated HDL formed clear precipitin rings on apo A-I and apo A-II SRID plates, but formed unclear rings on apo A plate. These difference of the reactions between anti apo A serum and delipidated HDL seems to suggest that immunoreactivity of HDL was not identical with that of apo A-I or apo A-II.

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We measured levels of total cholesterol (TC), HDL-cholesterol (HDL-C), apolipoprotein A-I (A-I) and A-II (A-II) in 371 boys and 354 girls ranging in age from 6 to 14 years. Level of TC began to decrease from age 10 and remained low level during the period of junior high school. Level of HDL-C remained constant level during the period of elementary school. In girls from age 13, level of HDL-C increased and the difference between sex appeared. Level of A-I showed similar change as the level of TC, that is, decreased from age 10 and then remained low level. Level of A-II began to decrease from age 9 and remained low level, then began to increase from age 13. A-I/A-II ratio was constant during the period of elementary school. In boys from age 13, A-I/A-II ratio began to decrease.

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The secretion of apo A-I and E from primary cultured rat hepatocytes was studied. Isolated hepatocytes were prepared according to the modified method of Berry and Friend. Both apo A-I and E concentrations in culture medium were measured by specific double antibody radioimmunoassay.
During the incubation of first 24 hours, the amounts of both apoproteins secreted from hepatocytes into culture medium increased linearly in relation to time. The amounts of apo E secreted from hepatocytes were about 4 fold greater than those of apo A-I, while plasma apo A-I levels were higher than apo E.
It is proposed that primary cultured hepatocytes are useful tools for studying apoprotein synthesis.

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The purpose of the present study was to investigate the synthesis of very low density lipoprotein in primary monolayer culture of hepatocytes prepared from streptozotocin-induced diabetic rats. Adult rat hepatocytes were cultured in serum free culture medium, HI/WO₅/BA₂₀₀₀ (International Scientific Industries Inc., Cary, Ill.). Liver cells were isolated using collagenase according to the modified method of Berry and Friend. Approximately 2.5-3.0×10⁶ isolated liver cells in a final volume of 2.5ml of culture media supplemented with Gentamicin were inoculated into plastic culture dishes (diameter=60mm)(Falcon Plastics, Oxnard, Ca.) which had been coated with calf skin collagen (type III) and fibronectin (Collaborative Res.). The culture dishes were placed in a humidified incubator under 5% CO₂/95% air at 37°C. After 4 hours of culture, the inoculated cells adhered to the bottom of the culture dishes and the culture medium was changed to remove cell debris and loosely attached cells. Conditioned medium was concentrated by Diaflo® ultrafiltration membrane YM 10 approximately 10 times and concentrated medium was ultracentrifuged sequentially at the densities of 1.006, 1.063 and 1.210g/ml. Lipoprotein fractions were dialyzed against 0.15 M NaCl with 3 mM EDTA, pH 7.4. Cholesterol (Ch), triglyceride (TG), phospholipid (PL) and protein in VLDL, LDL and HDL were measured. Time dependent increase of concentration of VLDL-TG in the culture medium was observed. VLDL-TG in the culture medium after 12 and 24 hours incubation were 8.2±1.2 and 23.1±1.9μg/mg cell protein, respectively. Electron-microscopic features of VLDL particles in the culture medium were comparable to those of plasma VLDL. Synthesis of VLDL in the cultured hepatocytes prepared from streptozotocin-induced diabetic rats was approximately 1/10 of control rats (0.6 vs 8.2μg/mg cell protein at 12 hours incubation). These observations suggest that synthesis of VLDL in the liver does not play a significant role in increased concentrations of VLDL observed in the insulin-deficient diabetic rats.

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In rats fed soybean phospholipid, concentration of serum cholesterol and apo A-I decreased and that of apo B (especially high-molecular-weight apo B) increased significantly compared to rats fed soybean oil. The reduction of serum apo A-I and cholesterol in rats fed soybean phospholipid appeared to be due to the decreased secretion from the liver as well as intestine, while the increase in the serum apo Bh being due to delated clearance from the circulation. Among the phospholipids tested, phosphatidyl-ethanolamine or its constituent base was the responsible for the alterations described above.
These results suggest that dietary phosphatidylethanolamine or ethanolamine have relevance to the regulation of serum lipoprotein metabolism.

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We have reported previously that cholinephosphotransferase (CPT) activity, which catalizes de novo synthesis of phosphatidylcholine (PC) from diacylglycerol and CDP-choline, was greatly increased in atherosclerotic lesion, and that this may explain well-known fact of increase in PC in the lesion. It has also been recognized that cholesterol content in the membranes of subcellular organelles is increased in atherosclerotic lesion. In this study, the effect of cholesterol in microsomal membrane, where CPT is located, on CPT activity was investigated. Incubation of rat aortic microsome with preincubated mixture of lysosome and low density lipoprotein (LDL) at pH 4.5 increased CPT activity twofold, showing that the catabolism of LDL by lysosome could be related to activation of CPT in microsome. Cellular cholesterol in arterial cells is mainly derived from LDL through cholesteryl ester hydrolysis by lysosomal cholesterol esterase. This implies that cholesterol could be a regulatory factor of CPT. In order to increase cholesterol content in microsomal membrane, rat hapatic microsome was treated with 0.5% heparin and reconstited with PC liposomes containing varying amounts of cholesterol.
Microsome treated with heparin had lower density than intact microsome when examined by sucrose-gradient centrifugation. After centrifugation at 105, 000×g at 60min, the pellet fraction of heparin-treated microsome was used for reconstitution with liposomes in the presence of octylglucoside. Cholesterol content in microsome reconstituted with PC/cholesterol liposome was increased and associated with increased CPT activity on sucrose-gradient centrifugation profile. CPT activity of reconstituted microsomes was increased with increasing concentrations of diolein up to 2mM: The maximum PC synthesis by PC/ cholesterol liposomes was more than twice higher than that by microsome reconstituted without liposome, whereas microsome reconstituted with cholesterol-free liposome showed slightly higher activity. The kinetic parameters of CPT with CDP-choline showed that PC/cholesterol liposomes decreased Km for CDP-choline and increased V_max. The increase in V_max by PC/cholesterol liposomes was parallel with cholesterol content in liposomes. Cholesterol-free liposome did not change V_max of CPT activity. These results suggest that increase in cholesterol content in microsome in atherosclerotic lesion might activate CPT activity by altering the conformation of CPT in the membrane.

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To study the disturbance of metabolism of plasma lipids and apoproteins in a familial lecithin: cholesterol acyltransferase deficiency, the effects of a low fat diet on plasma lipids, apoproteins and plasma enzyme activities were investigated. The plasma apoprotein A-1 and E levels were measured by a radioimmunoassay. The apoprotein B level was determined by the method of a single radial immunodiffusion. Lipoprotein lipase and hepatic triglyceride lipase activities were measured by an immunochemical method utilizing antiserum prepared against hepatic triglyceride lipase. By the restriction of fat in diet, the amount of triglyceriderich lipoproteins were decreased. Also, plasma apoprotein E and B levels were markedly decreased, while the improvements of both lipoprotein lipase and hepatic triglyceride lipase was not observed. These results suggest that high plasma apoprotein E in the familial lecithin: cholesterol acyltransferase deficiency is strongly related to the disturbed triglyceride-rich lipoprotein metabolism in the lecithin: cholesterol acyltransferase deficient state.

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3.5% polyacrylamide gel electrophoresis in 0.1% sodium dodecyl sulfate was employed to separate the apoprotein (apo) B subclasses, apo B-100 and apo B-48, of very low density lipoproteins (VLDL), intermediate density lipoproteins (IDL) and low density lipoproteins (LDL) in patients on maintenance hemodialysis and in normal controls. The results were as follows.
1) In uremic patients, there was significantly an increase in the percent apo B-48 of VLDL and a reverse change of the apo B-100/B-48 ratio.
2) Similar results were obtained in relation to the distributions of apo B subclasses in IDL. In addition, some patients had a apo B-74 which could be a degradation product of apo B-100.
3) Small amounts of apo B-48 were detected in the LDL of some patients, while no apo B-48 was observed in the LDL of normal controls.
4) There was no significant relationship between serum triglyceride levels and the existence of apo B-48 in each apo B-containing lipoprotein of patients on maintenance hemodialysis.

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It is well known that uremic serum lipoprotein abnormalities are associated with a decrease in serum lecithin: cholesterol acyltransferase (LCAT) activity but the precise mechanism is not yet clear.
Thus, we investigated the in vitro effects of LCAT containing lipoprotein deficient fraction (LPDF) from a normal control on uremic lipoprotein fraction (LP). The incubation with the LPDF and LP was carried out for 12 hours, at 37°C. The resulting mixture was isolated by isopycnic density gradient ultracentrifugation and the pooled fraction corresponding each lipoprotein was used for the chemical determination and the quantitation of apoprotein (apo) A-I and apo A-II in high density lipoproteins (HDL). Consequently, the following findings were summerized.
1) In the absorbance of lipoprotein profiles, LPDF caused an increase in low density lipoproteins (LDL) and HDL₂, and a decrease in very low density lipoproteins (VLDL)-intermediate density lipoproteins (IDL) and HDL₃.
2) LPDF brought about an increase in total amounts of LDL and HDL₂, and a decrease in those of VLDL-IDL and HDL₃.
3) With respect to the chemical compositions, LPDF caused an increase in percent cholesteryl ester and a decease in phospholipid content in any lipoprotein fraction.
4) There was an increase in total amounts of apo A-I and apo A-II, and apo A-I/A-II ratio in HDL₂ and a reverse change in HDL₃ after the incubation of LPDF with the uremic LP.
These in vitro results strongly suggest that low LCAT activity in uremia may be related to a decrease in HDL₂.

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Serum lipids were studied in 17 patients with multiple myeloma. Total cholesterol, low density lipoprotein (LDL) and high density lipoprotein (HDL) cholesterol levels (mean±SD) were significantly reduced in 6 patients with plasma cells over 30 per cent in bone marrow compared to 28 normal subjects (103±34mg/dl versus 172±24mg/dl, 46±19mg/dl versus 94±17mg/dl and 39±21mg/dl versus 53±11mg/dl respectively). Otherwise, hypocholesterolemia were not observed in 11 patients with small amount of plasma cells (less than 29%). There was a negative correlation between serum cholesterol and M-protein in multiple myeloma and also a rise towards a normal cholesterol level as a result of the effective treatment.
LDL catabolism is mainly mediated through the LDL receptor pathway in the parenchymal cells. The effect of M-protein on LDL receptor was studied in cultured human skin fibroblasts. No increase of LDL uptake and degradation was observed with M-protein.
Low serum cholesterol levels seems to be mediated by the high serum M-protein level or the great amount of plasma cells in bone marrow. Levels of serum total and lipoprotein cholesterol provide valuable informations in assessment of the disease activity.

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There were few reports regarding the relatively lower incidence of myocardial infarction in patients with pulmonary emphysema. To give a better understanding of this problem, we performed the present study. The results were as follows.
1. Fifty eight patients with chronic obstructive pulmonary diseases from 19 to 91 years of age were divided on the basis of the criteria proposed by Fishman into three groups, i. e., predominant emphysema, predominant bronchitis and other pulmonary diseases. And 191 healthy adults from 30 to 79 years of age were selected as a control. The serum cholesterol, triglycerides, phospholipids and lipoproteins were measured in every subjects from three groups. In majority of the patients, HDL-cholesterol subfractions and apoproteins were also determined.
2. There were no differences with levels of serum cholesterol and phospholipids among three groups, but serum triglycerides of the emphysema group was significantly lower than that of bronchitis group (111±6 vs 159±19mg; p<0.02).
3. The serum HDL-C concentration was significantly higher in the group of emphysema than in the group of bronchitis and in the control group (55.7±3.8 vs 39.8±3.7, 47.0±1.1mg; p<0.001, 0.01). The emphysema group also showed significantly higher level of HDL-PL than that of the normal control group (118±7.4 vs 98.7±1.6mg; p<0.001).
4. The ratio of HDL₂-C/HDL-C was higher in the emphysema group (72.1±2.0%) than in other groups. And serum Apo A-I level was higher in the emphysema group (136.2±5.4mg) as compared to the bronchitis group (118.4±3mg).
In conclusion, we found that patients with pulmonary emphysema have an increased level of HDL-C and HDL-PL. We believe that this finding may explain in part the decreased incidence of myocardial infarction among these patients. And mechanism of HDL-C increase in the emphysema patients was discussed from the view point of pulmonary surfactant metabolism.

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Myocardial cells were isolated from the mouse embryo and cultured in microplate. The effects of the Ca²⁺-antagonist (nifedipine, diltiazem) on frequency of spontaneous beating of the myocardial cells were studied and it was found that noradrenaline-stimulated beating was inhibited reversibly, by adding nifedipine (100ng/ml). Diltiazem (active form) showed an inhibitory effect at 1μg/ml on noradrenaline-stimulated beating while 10 times higher concentration of diltiazem of inactive form was required to exert a similar inhibitory effect. Nicomol and cadmium didd not affect the beating at 0.1μg/ml and 10μg/ml, respectively.

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Rat aortic smooth muscle cells in culture were exposed to various concentrations of iron and magnesium in order to assess their effects on cell proliferation, glucose consumption and lactate production.
Glucose consumption and lactate production were enhanced in the early stage of both exponential and stationary phases of cell growth.
Iron at physiological concentrations (10^-5M), or more, was effective to promote the proliferation of cells and to increase glucose consumption and lactate production.
The maximal stimulation to cell proliferation and glucose consumption by magnesium was observed at approximately 10% of physiological concentrations, whereas lactate production was most increased at 10 times the physiological concentrations.

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Sixteen human dissected aorta were classified into three histological types: Normal, fatty streak or fibrous plaque and atheroma.
The contents of lipids (total-cholesterol, esterified-cholesterol, free-cholesterol, triglyceride and phospholipid) and essential metals (calcium, magnesium, iron and zinc) of each specimen of the aorta were determined.
The results were as follow:
The concentrations of total-cholesterol, esterified-cholesterol, free-cholesterol, triglyceride and phospholipid were increased significantly with the progression of atherosclerosis and with age (p<0.05-0.01). Especially, esterified-cholesterol had markedly increased in atheroma. It was assumed that esterified-cholesterol was important for the pathogenesis of atherosclerosis.
The contents of essential metals such as magnesium and zinc increased significantly in fatty streak or fibrous plaque with the advance of atherosclerosis and with age (p<0.01, p<0.05), respectively.
On the contrary, calcium and iron were not significant. Calcium to magnesium ratio had decreased in fatty streak or fibrous plaque, and had again increased in atheroma, since the degree of magnesium content was greater than that of calcium.
There was significantly negative correlationship between iron and triglyceride at normal site (p<0.01) and significant positive correlationship between iron and free-cholesterol or phospholipid in fatty streak or fibrous plaque (p<0.05, p<0.01), respectively. Wherease no relationship was observed between essential metals and lipids in atheroma.
From the above results, it was suggested that iron might participate in the synthesis of triglyceride at the normal site and in the synthesis of free-cholesterol or phospholipid at the sites of fatty streak or fibrous plaque, and other metals (zinc, especially magnesium) might be anti-atherogenic.

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Minimal exposure time required to initiate DNA synthesis of aortic smooth muscle cells stimulated by the hyperlipidemic serum and its low density lipoproteins was measured using autoradiography in vitro. Both primary cultures and subcultures from the monkey thoracic aorta, stationary in 5% calf serum needed to contact with hyperlipidemic serum for 4 hours to initiate DNA synthesis. However subcultures required a slightly longer
time of contact with hyperlipidemic serum to initiate DNA synthesis and appeared less sensitive to hyperlipidemic serum stimulation as compared to primary cultures. The majority of responsive cells of both primary cultures and subcultures reacted to the stimuli of hyperlipidemic serum within short exposures (6-8 hours). Subcultures required about 8 hour-contact with hyperlipidemic LDL to initiate DNA synthesis and at least 50μg/ml LDL in proteins from hyperlipidemic serum was necessary to stimulate DNA synthesis.

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Three decimal eight per cent of the initimal smooth muscle cells of a normal rabbit aorta showed a synthetic phenotype. After rabbits were placed on an atherogenic diet for 1 or 6 weeks, existence of the synthetic typed cells in the intima increased to 38.8% and 55.6% respectively. In contrast, the frequency of that type in the media did not increase after switching from a normal to atherogenic diet. The number of labelled nuclei of the muscle cells in the aorta on [³H]-thymidine autoradiograms increased due to hyperlipidemia.
Cultures of the smooth muscle cells obtained from atherosclerotic plaques of rabbit aortas exhibited higher DNA synthetic rate and saturation density than normal medial cells. The passage, that is trypsinization of cultures did not influence on high rate of DNA synthesis. They lost the ability to form “hill and valley-arrangement” regarded as the characteristic pattern of growth for vascular smooth muscle cells in vitro.
Under an electron microscope the intimal cells were rich in RER, free ribosomes and large mitochondria, but scanty in myofilaments. In contrast, medial muscle cells were generally abundant in myofilaments representing a contractile phenotype of smooth muscle cells. Proliferation of smooth muscle cells in the intima is one of the most important phenomena in the development of atherosclerosis. The muscle cells in the intima may have enhanced response to growth stimuli as compared to medial cells. Therefore, control of phenotype or growth of intimal smooth muscle cells is a key point to prevent atherosclerosis.

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In the present paper, the effects of vitamin E and coenzyme Q₁₀ on the proliferation and the lipid contents of aortic smooth muscle cells (ASMC) obtained from hypercholesterolemic rabbits were studied in vitro. The normal rabbits were fed with ordinary chow and hypercholesterolemic rabbits were induced using the chow containing 1% cholesterol.
The effect of ethanol which is essential to solubilize vitamin E in culture medium (RPMI-1640 and 20% FCS) was the suppression of the cell proliferation of both normal and hypercholesterolemic ASMC and this effect was significantly recovered by the addition of vitamin E in culture medium. The normal and hypercholesterolemic ASMC showed no difference of lipid peroxide (TBA) contents.
The addition of vitamin E (5 ug/ml and 10 ug/ml) but coenzyme Q₁₀ in culture medium lowered the TBA content only in hypercholesterolemic ASMC.
The fatty acid analysis of ASMC showed that the ratios, oleate/stearate and palmitate/stearate, were same in normal and hypercholesterolemic ASMC and the addition of vitamin E rapidly made the significant increase of oleate/stearate in hypercholesterolemic ASMC but coenzyme Q₁₀ did not.

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Plasma levels of lipids and hematocrit (Ht) in survivors of cerebral infarction (C. I.) and patients with various diseases including hyperlipidemia were measured to study the relationships between lipoprotein metabolism and erythropoiesis.
The survivors of C. I. were divided into two groups according to the level of Ht. The mean level of plasma cholesterol in the group with Ht levels of 45% and over was higher than in the group with Ht levels below 45%.
The level of Ht was well correlated with the level of plasma cholesterol in patients with various diseases including anemia and hypercholesterolemia. In males, there was a weak correlation between Ht and triglyceride (TG) levels but not in females. HDL-cholesterol levels were independent of Ht levels in both sexes.
Treatment of anemia led to a rise in plasma cholesterol levels in a patient with iron deficiency anemia.
These results suggest the possibility that the metabolism of lipoprotein, especially of low density lipoprotein, has some effect on erythropoiesis.

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The effect of vitamin E on the lipid metabolism of erythrocyte membrane of experimental hypercholesterolemic rabbits was examined. Rabbits were divided into two groups. Group C: rabbits fed by a hypercholesterol diet. Group E rabbits fed by a hypercholesterol diet containing vitamin E. Erythrocyte Membrane lipids and lipids in the thoracic aorta were analysed.
Free cholesterol in the erythrocyte membrane of group C was not so much increased as that of group E. In group E, the decrease of polyunsuturated fatty acids (PUFA), particulary C₁₈₌₂, C₁₈₌₂ of erythrocyte membrane phospholipid was inhibited. Phospholipids in the aorta of group E contained more PUFA than that of group C. These data suggested that vitamin E had an important effect on membrane lipid metabolism.

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The impairment of blood fluidity facilitates the formation of ischemic lesion with respect to decrease in blood supply to tissues under the participation of changes in arterial wall and local blood pressure gradient. Functional compensation due to augmentation of blood fluidity for decrease in blood supply to tissues would protect even elderly adults with systemic arteriosclerotic changes from the occurrence of thrombotic diseases. Blood fluidity is influenced by corpuscular and plasma components in the blood. Erythrocytes participate to low blood fluidity by increasing viscosity and decreasing the deformability induced by low stroma ATP content and quality changes in membrane constituents affected by plasma lipids and lipoproteins. This study was intended to clarify fundamental association of serum lipids with erythrocyte membrane proteins as a part of lipid and hemorheological research in thrombotic cerebrovascular disorders.
Seventy-nine healthy adults with normal physical findings, blood pressures, urinalysis, blood sedimentation rate, chest films, ECG, liver function tests and serum lipids were selected for this study in the annual screening for circulatory disease. Blood specimens were drawn in the fasting state early in the morning. Erythrocyte membrane was separated by the method of Dodge et al., the membrane proteins were extracted and analyzed qualitatively using SDS-polyacrylamide gel disc electrophoresis by the method of Weber et al., Total cholesterol (TCh), triglyceride and phospholipid were determined by conventional methods, HDL-cholesterol (HDL-Ch) by MgCl₂-dextran sulfate method, LDL and VLDL by the precipitating method, and apo A-I, apo A-II and apo B by single radial immunodiffusion method.
Subjects aged above 60 years revealed significantly higher levels of TCh, LDL and apo B, and significantly lower levels of HDL-Ch and HDL-Ch/TCh ratio compared with those aged 20 to 39 years. Erythrocyte membrane band 2.1 connecting with spectrin affecting immediately erythrocyte deformobility was lower in subjects aged above 60 years than in those aged 20 to 39 years. In subjects aged 20 to 39 years, serum TCh, esterified Ch and LDL were directly proportional to spectrin 1, spectrin 2 and inversely to glucose 3 phosphate dehydrogenase, and HDL-Ch directly to band 4.1, 4.2, 8 and actin (Table 3). LDL was directly proportional to spectrin (band 1+2) (Fig. 2). In subjects aged 40 to 59 years, apo A-I was inversely proportional to actin, apo A-II directly to band 4.1 (Table 4). In subjects aged above 60 years, A-I was directly proportional to band 2.1 (Fig. 3). Neither of age groups showed significant relationships between serum unesterified Ch and membrane proteins.
Erythrocyte lipids are almost located in the membrane. The mature erythrocyte is incapable of the denovo synthesis of cholesterol. A notable feature of blood cholesterol is its ability to exchange between erythrocyte and plasma. Morphological observations have shown the appearance of various kinds of abnormal erythrocyte, which impaires hemorheological behavior following the changes of membrane lipids with regard to the membrane protein and stroma ATP. Although membrane lipids analysis is lacking in our study, intimate associations of serum lipids and lipoproteins with the membrane protein were shown. Therefore serum lipids should be regarded as one of important factors in the development of hemorheological disorders as well as the participation in atherosclerosis in thrombotic disorders.

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Until now, aortic tortuosity is understood as a sign of atherosclerosis. But, there was no quantitative approachh of abdominal aortic tortuosity. In this paper, we quantitatively evaluated the tortuosity with RI angiography. And, we already reported a quantitative method to evaluate aortic calcification from X-ray CT films. The Calcification Index (C. I.) calculated in its method has strong reration with aortic atherosclerosis evaluated by pathological method. So, we used C. I. as an atherosclerosis index.
Tortuosity becomes stonger with increasing age. C. I. also becomes higher with increasing age, but there is no relation between tortuosity and C. I.. When atherosclerosis is defined as local lesion, tortuosity is not a sign of atherosclerosis but of aortic aging.

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We already reported a quantitative method to evaluate the aortic calcification with X-ray CT. And, methods to evaluate calcium content in bones with X-ray CT were also reported by other people. So we used X-ray CT to analyze the relation between abdominal aortic calcification and vertebral body decalcificion.
Vertebral body decalcification progresses with increasing age. And we already reported that aortic calcification also becomes stronger with increasing age. So we analyzed the relation only in sixtes to exclude age factors. There is no relation between them.
Until now, some clinical or chemical studies concluded that there is a positive relation between aortic calcification and osteoporosis. But in clinical studies, where the aortic calcification was evaluated by conventional X-ray films, age factors were not excluded. And in chemical studies the aortic calcification was evaluated by the calcium content of homogenized aortic materials. In clinical or our study, aortic calcification means calcification on local atherosclerotic lesions.
There is no relation between aortic calcification and vertebral body decalcification, but may be positive relation between chemical calcium content of aorta and vertebral body decalcification.

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Serum levels of lipoproteins and apolipoproteins were investigated in untreated type 2 diabetic subjects without complications, and compared with those in age, sex matched non-diabetic subjects. In diabetics, very-low-density-lipoprotein triglyce-ride (VLDL-TG) levels were significantly higher, while high-density-lipoprotein cholesterol (HDL-ch) levels were slightly lower than non-diabetics. In regard of HDL subfractions, HDL₂-ch levels were slightly lower, but HDL₃-ch levels did not differ from those of controls. The relative content of triglyceride in HDL₂ subfraction of diabetics was higher than that of controls. Apolipoprotein A-I and A-II levels in serum decreased. A-I/A-II ratio was higher in diabetics, although HDL₂ sub-fraction which was thought to have higher A-I/A-II ratio, decreased in diabetics. This discrepancy between lipid and apolipoprotein levels in HDL subfractions suggests the presence of qualitative change in HDL₂ and HDL₃ particles.
We analysed the correlation between insulin secretion and levels of each lipoprotein. Insulin secretion related positively to atherogenic index, (Total-ch-HDL-ch)/HDL-ch (r-0.625, p<0.01), and negatively to HDL₂-ch (r=-0.524, p±0.05). Thus the lipoprotein metabolism tended to atherogenic in diabetics with hyper-insulin secretion. Our previous studies showed that in insulin-treated diabetics the lipoprotein metabolism changed to anti-atherogenic, such as the elevation of HDL-ch level. These contradictory results might be accounted for by the difference of effects of endogenous insulin which acts primarily in liver from those of exogenous insulin which acts exclusively in peripheral organs on lipoprotein metabolism.

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Familial LCAT deficiency is reported, which is the fourth Pedigree of that in Japan. A 35-year-old male was admitted to Chihaya Hospital complaining of pre-tibial edema and proteinuria. He had corneal opacities with a ring formation and normochromic anemia. His serum total protein was 4.2g/dl and amount of urinary protein was about 2.5g a day. Renal function tests showed mild disorders. BUN, serum creatinine, creatinine clearance and PSP (15') was 18.2mg/dl, 1.2mg/dl, 63ml/min and 26%, respectively. In regard to serum lipids, total cholesterol showed a slight decrease of 110mg/dl but HDL-cholesterol did a remarkable one of 3.6mg/dl. According to the lipoprotein pattern examed by agarose gel electro-phoresis, alpha and pre-beta lipoproteins didn't appear. Unesterified cholesterol was 97mg/dl, so the ratio of esterified cholesterol to total one presented a very low titer of 0.12. LCAT activity was 17.2 UNIT, which showed only 20% of the normal value. In the histological ecamination, light microscopic findings of the renal biopsy specimen revealed many foamy cells in the basement menbranes and mesangia of glomerular tufts. As a result of that, this pstient was diagnosed to LCAT deficiency. However, in this patient, characteristic target cells were not recognized. It was seemed that this was a reason why unesterified cholesterol increased to one and two tenths of the normal value at most in the composition of lipids of red blood cell menbrans.

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