Effect of the oral administration of γ-oryzanol on the levels of plant sterols in whole serum and HDL fraction was studied in 12 patients with hypercholesterolemia and it was examined whether the sterol fraction of γ-oryzanol is incorporated into HDL-cholesterol.
The sterol fraction of γ-oryzanol consisted of 21% campesterol, 11% β-sitosterol and 68% five other sterols. The plant sterols were found to react with the enzyme system for the determination of cholesterol, that is, campesterol and β-sitosterol reacted in the enzyme system at the rate of 48% and 88% of that of cholesterol, respectively, γ-Oryzanol itself did not react but its unsaponifiable matter reacted at the rate of 35% of cholesterol. It was therefore suggested that the free sterol fraction, which was considered to be the main form of γ-oryzanol in blood, may affect the determination of serum or HDL-cholesterol.
After the treatment with γ-oryzanol 300mg/day for 10 weeks, the concentrations of campesterol and β-sitosterol were increased by 43μg/dl and 15μg/dl in the HDL fraction, and 196μg/dl and 85μg/dl in whole serum, respectively. The sum of the increases of campesterol and β-sitosterol in the HDL fraction corresponded to 2% of the increase of HDL-cholesterol (2.8mg/dl) and that in whole serum corresponded to 6% of the increase of total cholesterol (4.6mg/dl).
These results indicated that the levels of plant sterols in the HDL fraction or whole serum must be taken into consideration in order to evaluate accurately the effect of γ-oryzanol on HDL-or total cholesterol.

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Effects of dl-α-tocopherol (VE) and dl-α-tocopherol nicotinate (EN) on plasma membrane structure of fibroblasts were examined by scanning electron microscopy. When fibroblasts derived from biopsy samples of human skin were cultured in Eagle's minimum essential medium, many microvilli and long microspikes were seen on the cell surface. Marked decreases in the number of microvilli and long spikes were found in fibroblasts cultured with the lipoprotein deficient medium. Further, various small pits appeared on the cell surface, suggesting damages of plasma membrane structure. By addition of 15μM of VE or EN to the lipoprotein deficient medium, these damages were protected and many microvilli and spikes were found on the cell surface.
Levels of free cholesterol and cholesterol ester, both C₁₆ and C₁₈ fatty acid ester, decreased in fibroblasts cultured with the lipoprotein deficient medium. Similarly phospholipids levels of the cells decreased. On the other hand, by addition of VE or EN, free cholesterol, cholesterol ester and phospholipids were kept at normal levels. Further, energy metabolism of fibroblasts cultured with the lipoprotein deficient medium was examined. VE and EN relieved the decrease of ATP contents of the cells induced in the lipoprotein deficient medium.
From these results, it is suggested that the damages of plasma membrane of fibroblasts are induced in the lipoprotein deficient medium and cholesterol and phospholipids of the cells are released into the medium. It is considered that VE and EN protect the membrane of the cells against these injuries and maintain cholesterol and phospholipids of the cells at the normal levels, and therefore that VE and EN are vital to keep the plasma membrane structure.

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In this study, the changes of the levels of serum lipids after single administration of Niceritrol (Perycit-Sanwakagaku) were observed.
The study was performed on 14 healthy controls and 31 patients with lipid disorders. One capsule containing 250mg Niceritrol was administered to each subject. Blood was collected before, one hour after and two hours after Niceritrol administration.
Lipoprotein fraction cholesterol was measured by gel electrophoresis and gas-liquid chromatography (GLC). The fractions of free fatty acid (FFA) were also measured by GLC.
Results:
1) Both in the healthy control group and in the patient group, α, pre β and β-lipoprotein cholesterol showed no significant change by Niceritrol administration.
2) The levels of serum total cholesterol also changed in neither group.
3) The levels of serum triglyceride decreased mildly but significantly in the healthy controls, but in the patient group, it showed no change.
4) In healthy controls, serum FFA decreased distinctly one hour after administration, but two hours after, it increased again. And such tendency was more prominent in females than in males. Each fraction of FFA changed in parallel with the change of total FFA. In the patient group, slight decrease of FFA was observed, but it was not statisticaly significant.
Conclusion:
The most prominent change of serum lipid observed in this study was the decrease of FFA in healthy controls. This chage was thought to be the result of supression of hydrolysis of triglyceride by Niceritrol in adipose tissue. Such effect of Niceritrol was not observed in patients in this study, therfore these results indicate that there is some metabolic disorder of triglyceride in adipose tissue level in these patients.

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Clinofibrate, a new hypolipidemic agent, was given to 26 patients with hyperlipidemia or diseases of biliary tract for 6-8 weeks at the daily dose of 600mg to examine the effect on biliary lithogenecity. After the drug administration, the ratios of molar concentration of phospholipids and cholesterol decreased and that of total bile acids increased. The mean lithogenic index calculated by the formula of Admirand and Small showed the tendency to decline but that of Hegardt, Dam and Holzbach et al. was not influenced by the treatment.
The effect of daily 600mg Clinofibrate on biliary lithogenecity was compared with that of 1500mg Clofibrate using 6 patients of them thereafter. Their lithogenecities were not affected significantly by Clinofibrate administration, but the molar ratio of cholesterol concentration was markedly increased and that of bile acids was reduced by Clofibrate administration for 6-8 weeks. Consequently, the biliary lithogenic index of the patients increased significantly by Clofibrate. Composition of biliary bile acids was affected by neither Clinofibrate nor Clofibarte.
Some differences was suggested between the actions of both drugs on the biliary lithogenecity as well as sterol metabolism.

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The effect of tocofibrate [tocopheryl 2-(p-chlorophenoxy) isobutyrate] on cholesterol level in rats fed high-fat cholesterol diet was studies. Lowering activity of tocofibrate in cholesterol level in blood was no less than that of clofibrate (ED₅₀ of tocofibrate; 98.0μmol/kg or 61.5mg/kg, and clofibrate; 920μmg/kg or 223mg/kg).
To elucidate the mechanism of tocofibrate, intracellular distribution of the compound in liver was investigated. This paper suggested that tocofibrate associated mainly with peroxisomes, and that the distribution clearly differed from both that of clofibrate and α-tocopherol.

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A method of subfractionation of single span HDL on 10% agarose gel column was evaluated in terms of particle size and chemical constituent. As judged by the measurement of diameters of particles on electron micrographs, HDL particles were subfractionated according to their size as elution progressed. Although gel chromatogram of whole HDL showed single peak of O. D. ²⁸⁰nm., lipid and apolipoprotein components, it was evident that HDL₂ and HDL₃ fractions were resolved on the basis of particle size and chemical composition.
In fractions which corresponds to HDL₂, apo AI/AII molar ratio was higher in female with higher HDL cholesterol levels and decreased as the elution progressed. In fractions which corresponds to HDL₃, the molar ratio was relatively constant (apo AI/AII=2) regardless of the HDL cholesterol level. Also it was noticed that, in individuals with low HDL cholesterol level, apo AI/AII molar ratio was less than two in the fractions of larger HDL₃ particle and was greater than two in the fraction of smaller HDL₃ particles. The (colesterol+phospholipid)/apo (AI+AII) ratio decreased as the elution progressed. Thus the present method seems to be useful to characterize the heterogeneity of HDL populations.
This technique was also used to evaluate the effect of pantethine on serum HDL in three male subjects with hypoalphalipoproteinemia. In a case in whom only serum apo AI increased, rise in apo AI/AII molar ratio of smaller HDL (which corresponds to HDL₃) was seen. While, in another case in which both AI and HDL cholesterol increased, not only apo AI/AII molar ratio of smaller HDL but that of larger HDL also increased. Thus, pantethine brought about changes in the constituent of both HDL₂ and HDL₃ subfractions, indicating that evaluation of drug effect necessitates measurement of apolipoprotein as well as HDL cholesterol.

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Two major subfractions of high density lipoprotein (HDL), HDL₂ and HDL₃ were isolated by a single zonal ultracentrifugation. HDL₂ and HDL₃ were isolated into two distinct peaks. Isolated HDL₂ and HDL₃ were homogeneous in molecular size as revealed by the gradient polyacrylamide gel electrophoresis and the estimated molecular weight of each fraction were 350, 000 and 190, 000, respectively. Each fraction reacted against anti A-I and anti A-II serum but not against anti B and anti albumin serum by the double immunodiffusion technique. A-I/A-II ratio was estimated by polyacrylamide gel electrophoresis in 6M urea and revealed 3:1 in HDL₃ and 10:1 in HDL₂. By quantitative immunoelectrophoresis (electroimmunoassay), A-II was not detected in unconcentrated HDL₂ fraction while it was observed in HDL₃ fraction. A significant amount of A-I was found in both HDL₂ and HDL₃ fraction. Chemical analysis of HDL₂ from four male subjects showed 45% of protein, 21% of cholesterol 24% of phospholipids, and 11% of triglycerides. The values for HDL₃ were 60% of protein, 12% of cholesterol, 22% of phospholipids, and 6% of triglycerides. Serum specimen from a male type IIb hyperlipidemic patient subjected for analysis of HDL subfraction and found a very small peak of HDL₂ against normal size of HDL₃ peak. HDL subfraction of a male patient with alcoholic cirrhosis showed predominance of HDL₂ with no visible HDL₃ peak. Decrease in both HDL₂ and HDL₃ fractions was observed in a male patient with chronic hepatitis.

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Immunochemical quantitative analysis of Apo A-I is a very valuable and convenient method of clinical evaluation.
However, if possible, it is desirable to evaluate Apo A-I by this method without pre-treatment of the serum sample, i. e., the serum sample should be kept at a level with 300, 000-400, 000 as its average molecular weight, 1.063<d<1.112 as its specific gravity, and its electro-movement in the α1 fraction. To ideally satisfy these conditions, the sample should be composed by Apo A-I and phospholipids forming a uniform complex protein with a molecular size of 100Å.
Therefore, as a standard substance for immunochemical quantification, a new substance was semisynthesized anaerobically with pure Apo A-I and lecithin and lyso-lecithin under the ultra-short wave irradiation and its physical, chemical and immunochemical characteristics were evaluated similarly to HDL₂-A-I.
Using this standard substance, normal Japanese pooled serum (Q-S serum) was evaluated as substandard and a trial evaluation in myocardial infarction was carried out.

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Serum lipids and lipoproteins in 77 patients with arteriosclerosis obliterans (ASO) and in 34 patients with thromboangitis obliterans (TAO) were analyzed in detail. The following results were obtained.
1. There were no differences in levels of cholesterol and triglyceride between ASO and TAO.
2. β-lipoprotein were increased in both diseases.
3. High density lipoprotein cholesterol, lecitincholesterol acyl transferase (LCAT) and apoprotein-A were decreased in both ASO and TAO.
4. Extra pre-β lipoproteins were positive in about 20% of patients with both ASO and TAO. There were no differences in its incidence between patients with these diseases and normal person.
5. There were no remarkable changes in the composition of HDL₂ and HDL₃ in ASO and TAO.
6. As to serum lipids and HDL-cholesterol, there were no differences between ASO and TAO.
7. HDL-cholesterol was lower in patients with aorto-iliac occlusion than that in patients with femoro-popliteal occlusion in ASO.
8. HDL-cholesterol was lower in patients with rest pain or gangrene than that in patients with intermittent claudication in ASO.
9. Level of HDL-cholesterol in ASO patients with past history of myocardial infarction or cerebral vascular disease were lower than that in patients without those.

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It has been indicated that lipoprotein lipase (LPL) and hepatic triglyceride lipase (H-TGL) play a role not only in the metabolism of triglyceride rich lipoproteins but also in HDL metabolism. The purpose of the present study was to investigate the role of LPL and H-TGL in the metabolism of HDL-subfractions, HDL₂ and HDL₃ in the subjects with hypo-high density lipoproteinemia. Clinical diagnosis of the 29 patients with hypohigh density lipoproteinemia studied in the present study were postapoplexy in the steady state, coronary heart disease and hypertension etc. Furthermore, seventeen hypo-high density lipoproteinemia with diabetes mellitus, 19 subjects with normal levels of HDL-cholesterol (C) and 8 diabetics with normal levels of HDL-C were studied. Hypo-high density lipoproteinemia was defined by (HDL₂+HDL₃)-cholesterol less than 40mg/100ml. Plasma lipoproteins were fractionated by sequential ultracentrifugation at densities 1.063 and 1.110g/ml to obtain VLDL+LDL(d<1.063g/ml), HDL₂(1.063<d<1.110g/ml) and HDL₃ (d>1.110g/ml). Concentrations of cholesterol, triglyceride and phospholipid in plasma and each lipoprotein fraction were measured. Activities of LPL and H-TGL in postheparin plasma obtained 10min after injection of heparin, 10U/Kg body weight, were assayed utilizing the substrate containing [¹⁴C] triolein. Separate assay of LPL and H-TGL activities were performed by inhibition of LPL activity by 1M NaCl. Cholesterol concentrations in HDL₂ and HDL₃ from hypohigh density lipoproteinemia were significantly lower than those from the patients with normal levels of HDL-C. Decrease of HDL₂-cholesterol was more remarkable than that of HDL₃-cholesterol. Therefore, HDL₂-Ch/HDL₃-Ch ratio was significantly lower in hypo-high density lipoproteinemia than in the patients with normal levels of HDL-Ch. As far as phospholipid is concerned, the same tendency was observed as cholesterol. There was no significant difference in triglyceride concentration in HDL₂ and HDL₃ between hypo- and normo-high density lipoproteinemia. LPL activity was significantly lower in hypo-high density lipoproteinemia without diabetes mellitus than in normo-high density lipoproteinemia. There were no significant differences in H-TGL activities among 4 groups. In hypo-high density lipoproteinemia, significantly negative correlations were observed between H-TGL activities and concentrations of cholesterol and phospholipid in HDL₂. Significantly positive correlations were observed between LPL activities and concentrations of triglyceride and phospholipid in HDL₂. However, there were no significant correlations among LPL activity, H-TGL activity and lipids concentrations in HDL₃. These correlations were much more obvious in diabetics with hypo-high density lipoproteinemia. The data presented indicate the important role of LPL and H-TGL in the metabolism of HDL₂ and HDL₃ in the subjects with hypo-high density lipoproteinemia.

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HDL can usually be divided into two subfractions, HDL-2 (1.063<d<1.125) and HDL-3 (1.125<d<1.21), but little is known about the function of these subfractions. Recently, the effects of VLDL-lipolysis upon the structure of HDL-3 was reported by Eisenberg, Patsch et al., and they have shown that HDL-3 could be converted to HDL-2-like particles. This time, we incubated whole HDL, HDL-3 and HDL-2 with VLDL separately, and obtained the following results.
(1) The lipolysis of VLDL by lipoprotein lipase was completelly inhibited by 1M-NaCl and also moderately inhibited by 1mM-DTNB (LCAT-inhibitor).
(2) When VLDL was incubated with whole HDL and HDL-3, HDL-2 increased and HDL-3 decreased on the contrary. But, HDL-3 did not increase when VLDL was incubated with HDL-2.
(3) We speculated from these experiments that HDL-3 could be converted to HDL-2 fraction during lipolysis of Very Low Density Lipoproteins.

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To study the change in serum HDL levels with hypovolemic shock due to hemorrhage, blood from five female rabbits was withdrown from catheter inserted through carotid artery into aortic arch. Intermittently withdrown 3-5ml blood which accerelated condition of hemorrhagic shock was served for lipid and lipoprotein analysis. During the experimental period portal blood flow, mean blood pressure of aortic arch and indocyanine green test (R15) were frequently measured in those rabbits.
(1) Serum concentration of HDL-cholesterol, HDL-phospholipids (d.>1.063 which involve VHDL-phospholipids) gradually decreased and total and LDL+VLDL cholesterol and phospholipids showed a slight decrease immediately after biginning of experiment and kept constant there-after.
(2) The magnitude of decrease of the lipids was higher in HDL₂ than HDL₃ fraction and VHDL-phospholipids did not show any change by hemorrhagic shock.
(3) Lipid and protein composition of HDL₂ revealed a significant decrease of percent cholesterol and phospholipids accompanied by relative increase of percent protein and triglycerides and that of HDL₃ showed no change in the serum 270 minutes after shock.
(4) Substantial high elevation of catecholamine, temporal increase of NEFA and slight increase of serum triglycerides were observed during experimental period.

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We measured serum lipid peroxide (LPO) and HDL-cholesterol levels in patients with prostatic cancer before and during the course of anti-androgenic treatment. The patients under the anti-androgen treatment showed significantly higher serum LPO and HDL-cholesterol levels than those of non-treated patients. The patients who suffered from cardiovascular disease during the anti-androgen treatment sumed to be classified into two groups in terms of serum LPO, triglyceride (TG) and HDL-cholesterol levels. In one group, remarkable elevation of serum TG and LPO levels was observed after the initiation of anti-androgen administration, while serum HDL-cholesterol levels were raised only slightly. In another group, anti-androgen administration caused remarkable elevation of serum HDL-cholesterol levels, but evident change of serum TG and LPO levels. In some of the anti-androgen treated patients, rivoflavin tetrabutyrate was administered to prevent these anti-androgen induced abnormalities of serum lipids levels. The elevated serum TG and LPO levels were lowered, and simultaneously serum FFA levels were raised. No remarkable change was observed on serum HDL-cholesterol levels. It is tempting to assume that anti-androgenic agents may have suppressed TG-lipase activity and it may be recovered by the administration of rivoflavin tetrabutyrate.

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The importance of determining high-density-lipoprotein cholesterol (HDL-C) concentration has been unequivocally confirmed by the results obtained in several prospective studies. At the same time, it is shown that the concentration of HDL-C may largely fluctuate under the influence of many factors. The level of HDL-C is usually evaluated as a predictor of atherosclerotic vascular disease. Hence, in the present study attempts were made to thoroughly examine the reproducibility of the HDL-C level and the factors affecting it.
(1) The HDL-C levels were repeatedly measured in 28 healthy males and 29 healthy females to determine their reproducibility. Of the male subjects, three showed marked increases in HDL-C levels (more than 20mg/dl) accompanied by concomitant increases in apo A-I level, but no factors previously reported could be considered responsible for these changes. It is likely that these subjects might have been undergoing subclinical damage to the intestine or liver at the time of the initial examination followed by natural convalescence. When these particular cases are excluded, the mean variations are 4.9mg/dl for males and 8.1mg/dl for females. These results lead us to conclude that the second value of HDL-C which was determined at least one month later should fall within the experimental error of the first value to estimate the HDL-C level inherent to the individual. When the HDL-C level was measured in patients, the mean variations were much larger than those in healthy subjects.
(2) It is well established that the serum HDL-C level negatively correlates with the serum triglyceride level in cross-sectional studies. In fact, significant negative correlations were found among each of the whole male and female groups we examined, including patients with various diseases and healthy subjects. When these cases were divided into 13 groups according to the underlying diseases, and the correlation between HDL-C and triglyceride levels was examined in each group, no significant negative correlation could be observed except for two groups. In the present study, serum HDL-C and triglyceride levels were reexamined in 28 healthy males and 29 healthy females after some intervals, which averaged 8 months for males and 12 months for females. Hence, whether or not the difference in the HDL-C level correlated with the difference in triglyceride level between the first and second examinations was studied. No significant negative correlation was found in this longitudinal study.

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Two kinds of lipoprotein of ultra-watersoluble (UWS)-LDL and non-watersoluble (non-WS)-LDL were separated from serum LDL which was fractionated by Havel's method.
Cholesterol, triglyceride and binding hexose in UWS-LDL and non-WS-LDL were measured in 20 cases with cerebral thrombosis, 9 cases with cerebral haemorrhage and 10 healthy persons.
1) There are clear differences in serum concentrations of UWS-LDL and non-WS-LDL between cerebral thrombosis and cerebral haemorrhage, or cerebrovascular diseases and healthy persons.
2) It is useful to separate into two kinds of lipoprotein from LDL, as the concentrations of lipids and binding hexose in UWS-LDL and non-WS-LDL are different each other by the kinds of stroke.
3) Statistical differences are found in the rate of lipids to binding hexose, “namely lipids per unit lipoprotein” between cerebral thrombosis and cerebral haemorrhage, or cerebrovascular disease and healthy persons.
4) Serum lipoproteins in patients with cerebral thrombosis differ quantitatively and qualitatively from those in patients with cerebral haemorrhage, and also the same result was obtained between cerebrovascular diseases and healthy persons.

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In order to evaluate the left ventricular function in patients with ischemic heart disease, echocardiographic analysis of the mitral valve motion was made during ergometer exercise with minitoring heart rate, blood pressure, ECG and symptom.
The materials consisted of 25 patients with effort angina, 12 patients with myocardial infarction and 15 normal subjects as a control. The graded exercise was performed in supine position on the bed. Echocardiographic paramaters, such as maximal amplitude of the anterior mitral valve leaflet motion (Amplitude), diastolic descent rate (DDR), nitial opening velocity (opening rate) and final closing velocity (peak ds/dt), were measured at rest and after exercise. Peak ds/dt was compared with the change in the left ventricular end-diastolic pressure (LVEDP) and ejection fraction (EF) measured by angiography.
The results were that opening rate and peak ds/dt were decreased after exercise in patients with ischemic heart disease. These paramaters appear to be useful to assess the left ventricular reserve in patients with ischemic heart disease.

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To study the morphological changes in the endothelial surface of the artery due to wall shear stress load, an arterio-venous shunt was constructed between the common carotid artery and the external juglar vein in 7 dogs. One week postoperatively, the arterial segment proximal to the shunt anastomosis was resected and processed for scanning electron microscope (SEM), after measuring blood flow rates in vivo through the shunted artery (fs) and the ipsi-lateral control artery (fc).
The SEM observation of the endothelial surface demonstrated clear ultrastructural changes in the shunted artery in accord with the extent of the wall shear stress load proportional to the flow ratio fs/fc. In constrast with smooth surface of the control artery with regular folds of around 25μm in width along the longitudinal axis of the vessel, the shunted artery in 5 animals in which fs/fc was greater than 1, revealed to have quite rough surface with no clear folds but small swellings of spindle shape which were 4 to 5μm in width and some 15μm in length and were diffusedly distributed on the surface at the rate of approximately 30 spots per 10⁴μm². In some cases, fine traverse wrinkles of 0.5 to 1.0μm in distance were observed on the surface with the disturbed folds and swellings. In 2 animals in which fs/fc was slightly less than 1, however, the shunted artery showed no such changes and well resembled the ordinary feature of the control artery.
From these findings, it was concluded that the ultrastructural changes observed at the endothelial surface were induced by the wall shear stress load due to increased blood flow and that the effect of the stress load increasing the trans-endothelial permeability of the plasma protein as being demonstrated by many physiological studies, could be explained by these deformative changes of the endothelial layer. A possible role of the wall shear stress in atherogenesis was suspected.

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A new acid-stable phosphorylation was found to be formed in the presence of ATP and Ca²⁺ in a microsomal protein isolated from bovine aortic smooth muscle. The microsomes also showed Ca²⁺-uptake activity. Both of the Ca²⁺ dependency of the phosphorylation and the Ca²⁺-uptake were in the same range (1-10μM) and the patterns were quite identical to those of rabbit skeletal microsomes. The molecular weight of the phosphorylated protein estimated with SDS-gel electrophoresis was approximately 105, 000. The phosphoprotein was labile at alkaline pH after the denaturation and its decomposition was accelerated by hydroxylamine. The phosphorylation formed in aortic microsomes was thus quite similar to the acid-stable phosphorylated intermediate of the Ca²⁺-transport ATPase of sarcoplasmic reticulum from skeletal and cardiac muscles. These data suggest that the Ca²⁺-dependent phosphorylation of the protein is formed as a reaction intermediate of the Ca²⁺, Mg²⁺-ATPase of the aortic microsomes.

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Atherosclerotic cardiovascular diseases are leading cause of death in the diabetics who have hyperlipidemia.
To study lipoprotein metabolism in diabetics, streptozotocin diabetes was induced in rat as a good model for study of human insulin-dependent diabetics. We attempted to study the in vivo metabolism of esterified cholesterol in plasma high density lipoprotein and also in low density lipoprotein (d<1.063) of the diabetic rats.
Diabetic rats, pre-fed and maintained on a purina chow which contained 4.5% fat by weight, had marked hypertriglyceridaemia and rather increased HDL-cholesterol. HDL obtained from non-diabetic rats and labeled with ³H in the esterified cholesterol moieties was injected to diabetic and non-diabetic rats. Blood samples were obtained from tail vein at 15, 30 min, or 1, 2, 4, 8 hours after the injection.
The decay of ³H in the esterified cholesterol moieties from plasma was bi-exponential in both diabetic and non-diabetic control rats. Also, the decay of labeled HDL in the plasma was biexponential in the two group of rats.
Following injection of labeled HDL, radioactivity recovered from low density lipoprotein at all time interval was less than 2.1% and did not show any peak activity in both groups of rats.
Fractional catabolic rate (FCR) were calculated following the curve peeling technique as described by Matthews at steady-state conditions. FCR and half life of esterified ³H-cholesterol in the diabetic plasma were faster and shorter than those of non-diabetic rats (p<0.01). Also, FCR and half life of esterified ³H-cholesterol in the HDL of diabetic rats were faster and shorter than those of non-diabetic rats (p<0.1).
These results suggest that the synthesis and catabolism of HDL cholesterol ester are enhanced in the untreated streptozotocin diabetic rat.
An increase in HDL cholesterol ester turnover may reflect the enhanced catabolism of body nutritional reserves in uncontrolled diabetes mellitus.

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It is thought that multi-factors may relate to the occurence and exaggeration of arterial sclerosis in diabetes mellitus. We pointed out the calcification of peripheral arteries in the legs on X-ray photographs as a sign of arteriosclerosis, and studied its prevalence in diabetics and nondiabetics. Furthermore, in order to clarify what correlates with the arteriosclerosis, we analysed the laboratory data and studied the differences between the diabetics with or without the peripheral arterial calcification.
We concluded that the incidence of the peripheral arterial calcification in diabetics (32%) was twofold higher than that in non-diabetics (16%).
It was clarified that the incidence of the calcification increased significantly in diabetics who had insulin treatment as compared with those who had oral agents or only diet therapy. Similarly, it was significantly higher in diabetics who were complicated with proliferative retinopathy than those who had simple or no retinopathy. And also, diabetics with longer duration of illness had significantly high incidence of the calcification as compared with those with shorter duration.
It was relatively higher frequency in diabetics who had hypertention and were controled poorly than those who had normotention and were controled well, respectively, but there was no significance between them.
There were no relationships between the peripheral arterial calcification and obesity, serum concentration of lipids, ischemic changes on ECG and aortic arch-calcification in diabetics.
These results suggested that the peripheral arterial calcification might relate to the metabolic derangement in diabetes mellitus.

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The levels of plasma lipoprotein, apo A concentration and the changes of chemical compositions of HDL-subfractions were studied in the same sixteen diabetics controlled under the different therapeutic measures. The results showed that the administration of sulfonylurea increased the TG-rich lipoproteins levels and decreased the apo A-I concentrations, whereas insulin treatment reversed the effects of the sulfonylurea administration. The administration of insulin also decreased the relatively high TG contents in HDL subfraction particles separated when the patients were administered of sulfonylurea.

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Diabetic patients have high susceptibility to microvascular complications and atherosclerosis. Hyperaggregability and hyperadhesiveness of platelets and decreased prostacyclin (PGI₂) production in vessel walls may play an important role in those vascular disorders.
In this paper aortic PGI₂ production, function of platelets and plasma and tissue lipoperoxide levels were investigated in an experimental system of alloxen diabetic rabbits.
Following results were obitained.
1) PGI₂ production in diabetic rabbit aorta (0.14±0.02ng/mg⋅wet weight) was significantly decreased compared with that in controls (0.32±0.10ng/mg⋅wet weight). Treatment of the diabetic animals with insulin for 10 days restored the PGI₂ production to normal level.
2) Hypersensitivity to ADP, increased MDA formation and decreased sensitivity to PGI₂ were observed in diabetic rabbits platelets. Treatment of the animal with insulin restored the platelet MDA formation to normal levels.
3) Plasma and liver lipoperoxide levels were elevated in diabetic rabbits and normalized by insulin treatment.
These results suggest that lipoperoxides overproduced in diabetic organ like liver may inhibit PGI₂ synthesis in vessel walls and in turn cause hyperreactivity of platelets resulting in the diabetic angiopathy.

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A study was conducted to investigate effect of oral administration of Pantethine (600mg/day) on changes in serum lipids in 136 subjects with hyperlipidemia obtained from 32 institutions in Tokai District, Japan.
During an observation period of 12 weeks, serum total cholesterol (p<0.001) and triglyceride (p<0.05) were significantly decreased, whereas HDL-cholesterol (p<0.001) increased, resulting in significant amelioration in atherogenic index (p<0.001). No significant differences in changes of serum lipids were observed between diabetics and non-diabetic subjects.
As compared with serum lipids in patients with type IIa and IV, serum lipids in those with type IIb were most improved with respect to both HDL-cholesterol concentration and the atherogenic index.
According to comprehensive evaluation of ameliorations in serum lipids, administration of Pantethine was assumed to be effective in 74.1%. Side effects were observed only in 3 cases; each one of eruption, nausea and diarrhea.
In conclusion, oral administration of Pantethine is found to be useful for elevation in HDL-cholesterol, through which further development of atherosclerosis may be prevented.

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We studied platelet sensitivity to adenosine diphosphate (ADP) and to prostacyclin (PGI₂) in 44 diabetic patients. Because the production of PGI₂ was decreased in the vessel wall of diabetic patients, the platelet sensitivity to PGI₂ was expected to be increased.
Platelet sensitivity to ADP was measured as follows: maximum aggregation was determined by using each concentration of ADP (0.5, 1.0, 2.0, 3.0, 4.0, 6.0μM). We calculated the concentration of ADP to provoke half maximum of the aggregation as the sensitivity to ADP. On the other hand, we measured the platelet sensitivity to PGI₂ according to the principle that platelet aggregation induced by ADP (5.0μM) was inhibited by each concentration of PGI₂ (0.10, 0.20, 0.30, 0.40, 0.50ng/assay; 0.10ng/assay is equal to 0.77nM) and PGI₂ concentration to cause 50% inhibition was calculated as the sensitivity to PGI₂.
Platelet sensitivity to ADP was 1.5±0.8μM in diabetic patients without retinopathy (normal; 1.9±0.7μM). In diabetic patients with either simple or proliferative retinopathy the sensitivity was 0.8±0.4 and 0.9±0.5μM, respectively. This means the sensitivity of platelet to ADP was increased significantly in diabetic patients with retinopathy as compared with diabetic patients with-out retinopathy and healthy subjects.
Platelet sensitivity to PGI₂ was 1.31±0.77nM in diabetic patients without retinopathy (normal; 1.23±0.39nM). In diabetic patients with either simple or proliferative retinopathy it was 1.62±0.62nM and 1.77±0.62nM, respectively. Contrary to our expectation, the platelet sensitivity to PGI₂ in diabetic patients with retinopathy was decreased significantly as compared with normal value. There was no correlation between platelet sensitivity to ADP and PGI₂ in healthy subjects, but there was a negative correlation in 44 diabetic patients (r=-0.49, p<0.005). There was no difference of the platelet sensitivity to ADP and PGI₂ between simple and proliferative retinopathy.
Conclusively, the abnormality of sensitivity to ADP and PGI₂ in diabetic patients results in developing diabetic retinopathy.

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To assess the effects of nicomol, an ester derivative of nicotinic acid synthesized in Japan, on the lipoprotein abnormalities found in patients with ischemic heart disease, plasma lipoprotein fractions were ultracentrifugally separated and examined before and after three months administration of this drug in a dose of 1.2 grams a day.
The subjects examined were 8 survivors of myocardial infarction and 6 patients with angina pectoris. Each fraction of ultracentrifugally separated VLDL and LDL was mixed with heparin Ca solution and then filtered with a Millipore filter. Fractions retained on the filter were used for the determination of their chemical composition. The HDL₂ and HDL₃ subfractions were delipidated with tetramethylurea and then electrophoresed on a polyacrylamide gel. The densitometry of these electrophoretograms permited us to determine the proportion of contaminating albumin.
The plasma triglyceride level was significantly decreased, whereas the total cholesterol levels remained unchanged. VLDL-triglyceride concentration was significantly decreased. Percentage content of triglyceride was also significantly decreased but percentage contents of phospholipid and protein were significantly increased. The LDL level was almost unchanged. Either HDL-cholesterol level or HDL: LDL-cholesterol ratio was increased. Their increases were small but reached a statistically significant level. The HDL subfractions, HDL₂ and HDL₃-cholesterol levels were also increased. The increase of the former level was greater than that of the latter level, resulting in the slight increase of HDL₂ to HDL₃-cholesterol ratio. In the HDL₂ subfraction, percentage contents of phospholipid and triglyceride were decreased whereas the percentage content of protein was increased. The percentage content of cholesterol remained unchanged. The chemical composition of HDL₃ subfraction changed in almost the same way as that of HDL₂ subfraction. No significant side effects were observed.
It was clearly shown that nicomol administration considerably affected the lipoprotein profile in patients with ischemic heart disease. The level of VLDL was decreased in association with the significant elevation of the HDL, particularly HDL₂-cholesterol level. Therefore, the changes in the lipoprotein profile found in the present study seem beneficial for protecting against the atherosclerotic vascular disease.

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The antiatherosclerotic effects of estrogen are well known, however, as the mechanisms involved have not been determined, we designed experiments in which strips of thoracic aorta from oophorectomized rabbits were contracted by the calcium ionophore A23187 and the inhibition of the contraction by estrogen and concomitant levels of cyclic nucleotides were determined. A23187 (10^-5M) increased the tension slowly but progressively and there was a concomitant decrease in cyclic AMP levels. While a dose-dependent relaxation occurred in strips contracted by A23187 with addition of theophylline (>10^-4M) or dibutyryl cyclic AMP (>10^-4M) to the bath, a prior addition of these compounds inhibited the contraction. Pretreatment of the strips with estrogen (2×10^-7M, 2×10^-5M) significantly prevented contraction of the strips as induced by A23187 and also prevented reduction in cyclic AMP levels, as induced by this ionophore. Cyclic GMP levels remained unchanged throughout. As the contraction of the arterial wall was inhibited by estrogen in an apparent association with a reduction in the levels of cyclic AMP, such would explain the antiatherosclerotic effects, as reduction in these nucleotide levels apparently induces atherosclerotic lesions in the arterial wall by enhancing vascular permeability.

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