Intimal accumulation of monocyte-derived lipidfilled macrophages is one of the earliest events in diet-induced atherogenesis. To better understand the functional alterations of macrophages in hypercholesterolemia, we determined several variables of rat peritoneal macrophages in regard to their spreading, migration and phagocytic activities, and superoxide anion production. Compared with macrophages from normal rats (NM_φS), macrophages from hypercholesterolemic rats (HM_φS) revealed a prominent spreading capacity on the surface with remarkable lamellopodia. Towards a chemotactic factor of Zymosan activated serum, HM_φS exhibited a greater chemotactic migration and pronounced aggregation than NM_φS. The NM_φS phagocytic activity of fluorescent latex beads was significantly heightened. By contrast, there was no significant difference in superoxide anion production between the two groups.
These results indicate that hypercholesterolemia may initiate and accelerate atherosclerotic processes, at least in part, by modifying a number of the functional properties of macrophages.

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In order to determine the impairment to glutathione redox cycle in cultured endothelial cells (ECs) under acidic conditions, we measured glutathione-dependent degradation of hydrogen peroxide (H₂O₂), H₂O₂-induced changes in cytosolic glutathione contents (GSH, GSSG), GSH and GSSG transport rates from ECs, and both glutathione peroxidase and reductase activities in an acidic pH medium. 1) Glutathione-dependent H₂O₂ degradation activities decreased by 19% at pH 6, and 52% at pH 4 as compared with those of pH 7.4 (p<0.01), respectively. 2) The basal GSH content of ECs under the acidic conditions fell by 17% at pH 6, and by 53% at pH 4 as compared with that of pH 7.4. The decrease in basal GSH content under acidic pH (pH 4) could be reversed by the change in pH of the medium pH 7.4 after 30 minute-acidic pH condition. After an exposure of 500μM H₂O₂, intracellular GSH content fell by 61% of the control level at pH 7.4 (p<0.01). The H₂O₂-induced decrease in GSH level under acidic condition was impaired at pH 6 by 50% (p<0.01) of the value of pH 7.4, and there was no response at pH 4. 3) Intracellular GSSG content increased to 2.6 times the control level at pH 7.4 (p<0.01), 4.7 times the control level at pH 6 (p<0.01), and 1.9 times the control level at pH 4 after exposure to 500μM H₂O₂. The H₂O₂-induced increase in GSSG level at pH 6 was 2.6 times greater than the value at pH 7.4 (p<0.001). 4) After exposure to 500μM H₂O₂, the release of GSSG from the cells at pH 6 decreased by 38% as compared with the value at pH 7.4 (p<0.05) and the release at pH 4 completely disappeared. 5) Both glutathione peroxidase and glutathione reductase activities progressively decreased as the pH of the medium decreased from pH 7.4 to pH 4.
These results indicate that glutathione redox cycle in cultured endothelial cell was profoundly impaired by way of the decreases in both glutathione peroxidase and reductase activities and GSSG transport from the cells under the acidic conditions. The impairment of active oxygen degradation under the acidic conditions may induce endothelial cell dysfunction.

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We studied cholesteryl ester exchange rate (CEER) in patients with OMI compared with control. The study included 19 men with old myocardial infarctions (OMI), 5 men with hyperlipidemia, and 18 healthy volunteers (control). CEER was measured by using ³H-Cholesterol labeled HDL which was added to the sample plasma and incubated at 37°C for 5 hours. After the incubation, VLDL and LDL were precipitated using the heparin-Mn method, and the radioactivity remaining in the supernatant HDL fraction was measured. Lipoproteins were fractionated by ultracentrifugation, and their lipids were measured by enzymatic method. Apoproteins were measured using the TIA method. Compared with control plasma, in OMI plasma there were significant increases in PL (p<0.01), the HDL composition ratio of FC and TG (p<0.05) and CEEB (p<0.01), and significant decreases in HDL-C (p<0.01), -2C (p<0.05), -3C (p<0.01), -Prot (p<0.01), -PL, -CE (p<0.05), -Mass (p<0.01), Apo-A1, -A2, -CIII (p<0.01), and LCAT activity (p<0.01). CEER showed a significant positive correlation with LDL-C, Apo-B, LDL-Mass and HDL-TG composition ratios, and showed significant negative correlations with HDL-C, -2C, -3C, -PL, -CE, -Mass, and Apo-A1. We concluded that the high level of CEER and the low activities of LCAT correlated with low HDL level in OMI. However, CEER may be influenced by lipoproteins levels, so it is necessary to measure CETP activities.

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The hypolipidemic and anti-atherosclerotic effects of EPA have been reported in some studies. We investigated the effects of EPA on lipid metabolism in hamster small intestine as compared to other dietary fats.
Male golden hamsters were fed the following diets for 20 days: a control diet, a diet containing 20% safflower oil, a diet containing 20% coconut oil, and a diet plus 300mg/kg EPA. The lipid levels were measured by the enzymatic method. Microsomal HMG CoA reductase (HMG-CR) activity was measured following by the method of Field et al.
1) EPA significantly decreased plasma TC and TC—HDL-C levels, and tended to decrease plasma TG levels. 2) Safflower oil failed to significantly change plasma lipid levels. Coconut oil significantly increased plasma TC, TG and TC—HDL-C levels. 3) EPA significantly decreased microsomal TC, FC, and TG contents in the small intestine. On the contrary, safflower oil and coconut oil increased these lipid contents. 4) EPA significantly decreased microsomal HMG-CR activity in small intestine. Safflower oil failed to cause significant change to microsomal HMG-CR activity, and coconut oil significantly increased it.
These results suggest that EPA causes a reduction in cholesterol synthesis and decreases microsomal free cholesterol contents. Based on this evidence, we conclude that LDL receptor activity can be regulated upward by the suppression of HMG CoA reductase activity with EPA, and consequently plasma cholesterol levels are lowered.

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Abdominal wall Fat Index (AFI), which indicates the ratio of visceral fat areas to subcutaneous fat areas were calculated using ultrasonography, and the index's correlation with coronary stenosis was investigated. The subjects were 80 patients (55 males and 25 females) whose body mass indices were 20 to 26. The coronary stenosis was evaluated by coronary angiography. Stenosis score was calculated as the sum of stenosis points of each fifteen AHA segments of coronary artery. The subjects were divided into 2 groups according to AFI.
There were no significant differences in the levels of serum total cholesterol, triglyceride and HDL-cholesterol, and the incidences of diabetes mellitus, hypertension and smoking, between high-AFI group (male≥1.0 and female≥0.7) and low-AFI group (male<1.0 and female<0.7).
The frequency of coronary stenosis and the coronary stenosis score were higher in high-AFI groups for both men and women than in low-AFI groups.
The results suggest that AFI is a risk factor for coronary stenosis.

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This study was designed to clarify the relationship between aerobic power level, nonspecific ST-T changes in exercise ECG and coronary heart disease (CHD) risk factors in Japanese females.
Oxygen intake per kilogram of body weight (VO₂max/wt), nonspecific ST-T change in exercise ECG (horizontal and sagging depression ≥1mm) and CHD risk factors were examined in 317 middleaged healthy females.
The findings were as follows:
1) The mean value of VO₂max/wt in the nonspecific ST-T changes in exercise ECG group (ST group) was significantly lower than that found in the normal ECG group (N group) (p<0.05). However, the higher the mean values of the risk factors (SBP, TC, LDL-c, TC/HDL-c) in the ST group after adjusting for the effects of age and percent body fat (% fat) (all p<0.01). There were no significant differences between the ST group and the N group in the mean values of DBP, HDL-c, and TG.
2) Significant correlations were observed between VO₂max/wt and CHD risk factors (each p<0.0001 except for TG<0.001).
From these results, it was concluded that VO₂max/wt may be closely related to CHD risk factors and nonspecific ST-T changes in exercise ECG. Also these results suggest that it may be necessary to maintain the VO₂max/wt to a high level for coronary heart disease prevention.

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The arteriographic features of patients with ischemic heart disease are diverse, ranging from normal coronary artery to severe multivessel disease. Although many investigators have considered lipoprotein (a) [Lp (a)] as an independent risk factor for coronary heart disease, the relationship between Lp (a) and diversing arteriographic feature of coronary atherosclerosis has not been fully resolved. In this study, we tried to analyze the relationship between Lp (a) and the arteriographic feature of coronary atherosclerosis.
Subjects are 230 patients with ischemic heart disease who underwent coronary arteriography. Patients were divided into four groups according to the coronary arteriographic findings (Group I: near normal group, Group II: diffuse minor group, Group III: solitary tight group, Group IV: diffuse tight group).
The following 16 variables were selected. The variables analyzed were age, sex, hypertension, diabetes mellitus, smoking, uric acid, obesity, total cholesterol, triglyceride, HDL-cholesterol, apolipoprotein A1, apolipoprotein B, apolipoprotein E, LDLC/HDLC, apo B/A1, and Lp (a). The relationship between these variables and the coronary arteriographic findings was analyzed by multivariate analysis.
Serum Lp (a) levels in each group was 15.9±9.3mg/dl in Group I, 23.6±18.7mg/dl in Group II, 10.8±7.8mg/dl in Group III, and 26.4±18.3mg/dl in Group IV, respectively. Patients in Groups II and IV revealed significantly higher serum Lp (a) levels than Groups I and III (p<0.05).
By logistic regression analysis, diabetes mellitus, age, LDL/HDLC and Lp (a) were determined as correlating factors in this order for Groups II and IV, i. e., groups with diffuse coronary atherosclerosis.
So, Lp (a) was considered to be one of the independent risk factors for the pathogenesis of diffuse coronary atherosclerosis. The stronger Lp (a) contributes to the pathogenesis of coronary atherosclerosis, the more prevalent and progressive the atherosclerosis can originate. Therefore, Lp (a) is one of the valuable parameters for the detection of the expansion and the severity of coronary atherosclerosis.

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To study the role of abnormal lipids metabolism in vasospastic angina, serum was obtained from 9 vasospastic patients (V. S. A. group) and 18 control subjects (C group), and was processed to measure the total cholesterol, triglyceride, HDL-cholesterol and apoproteins (Apo A-I, A-II, B, C-II, C-III, E). The serum was separated by the ultracentrifugation method to measure the lipids and apoproteins in each of the fractions. No difference in age, degree of obesity or glucose tolerance was noted between these two groups. The following data was obtained.
1) A slight increase in triglyceride was noted in the V. S. A. group, but it was not significant.
2) A statistically higher concentration of serum Apo E was detected in the V. S. A. group.
3) The amount of T. G. -rich lipoprotein increased significantly in the V. S. A. group.
4) Statistically higher HDL-cholesterol levels in the V. S. A. group were detected together with the higher Apo A-I and A-II levels in the HDL and VHDL fractions.
These results demonstrated both increased T. G. -rich lipoprotein (VLDL-Chol, VLDL-T. G., and LDL-T. G.) and an increased pathway of reverse cholesterol transport in V. S. A., which was suggested to be specific to vasospastic angina because of the similarity of the background of the two groups.
Abnormalities in lipid metabolism might be significant in the pathophysiology of vasospastic angina; furthermore, they may have an inhibitory influence on the progression of the coronary atherosclerosis.

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Diagnosis of familial hypercholesterolemia (FH) requires the assessment of LDL receptor function. The method for the assay of functional LDL receptor on lymphocyte using HMG-CoA reductase inhibitor has been reported by Lipsky et al. We developed a simplified method involving a modification of their method as follows: 1) Lymphocytes are cultured in a medium containing lipoprotein-depleted fetal calf serum. 2) Endogenous sterol biosynthesis is suppressed with pravastatin, HMG-CoA reductase inhibitor. In this culture system, proliferation of lymphocytes is dependent on an exogenous source of LDL cholesterol. Suppression of lymphocyte proliferation of FH heterozygote by pravastatin was significantly greater than those of the normal subjects and non-FH hypercholesterolemia when LDL-cholesterol level in the medium was 10μg/ml (p<0.001). The response of lymphocytes from non-FH hypercholesterolemic patient was like that of normal cells. Also, in FH homozygote, the addition of LDL cholesterol in concentration up to 10μg/ml did not show pravastatin-mediated inhibition of the lymphocyte response. The simplified method proposed here can easily assay the LDL receptor function by only one medium with concentration of LDL cholesterol (10μg/ml).

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Homocysteine, a metabolite of the sulfur amino acids, is reported to be one of the risk factors for atherosclerosis. It has been reported that accumulation of homocysteine produces atherosclerosis in young patients with homocysteinuria. Indeed, plasma levels of homocysteine were statistically higher in patients with myocardial infarction and those with cerebral infarction. However, the relationship between cholesterol and homocysteine levels remains unclear. In the present study, we reared rabbits on a diet supplemented with 0.2% cholesterol for 22 weeks to confirm the extent to which serum cholesterol affects the level of plasma cysteine and homocysteine. Plasma homocysteine, cysteine, serum cholesterol and triglyceride levels were estimated at two week intervals. No significant change in the plasma homocysteine or cysteine levels were noted compared to that in normal controls, despite a remarkable increase in serum cholesterol levels.
These findings indicate that the homocysteine level is independent of the serum cholesterol level.

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The localization of apo A-IV was examined in several organs of rats using an immunohistochemical technique. It is well known that rat apo A-IV is synthesized in the small intestine and in the liver. However, the catabolic site of apo A-IV has not been fully understood. In the present study, apo A-IV was positive in the epithelium of the small intestine, liver cells, and renal proximal tubular cells, and was negative in the large intestine. Apo A-IV was localized in villus epithelium both in the jejunum and ileum, and the intensity of staining for apo A-IV was greater in jejunum than ileum. The stained liver cells were scattered around the central vein. The positive findings both in the small intestine and the liver are compatible with the fact that these organs are responsible for the synthesis of apo A-IV. On the other hand, apo A-IV was also detected in renal proximal tubular cells when glomerulus was not stained.
Since it is considered that apo A-IV is not synthesized in the kidney, it is feasible that apo A-IV in the plasma passes through the glomerulus, and is then taken up by tubular cells as well as other lowmolecular-weight proteins.

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