An attempt was made to estimate the distribution of plasma HDL subclasses according to the levels of plasma lipids and apoproteins. Twenty-five normolipidemic patients, 25 hyperlipoproteinemic patients without CHD, and 28 CHD patients participated in this study. The distribution of plasma HDL subfractions was estimated by 4-30% gradient polyacrylamide gel electrophoresis (PAGE) of plasma fraction with a density of 1.21. The absolute amounts of HDL subfractions were obtained by multiplying HDL-C amounts by the percentage of HDL PAGE subclasses. Plasma concentrations of HDL_2b-C, HDL_2a-C, HDL_3a-C, HDL_3b-C and HDL_3c-C were 7.8±6.8mg/dl, 10.6±6.5mg/dl, 46.3±6.3mg/dl, 5.1±2.4mg/dl and 0.2±0.4mg/dl (mean±SD), respectively. Plasma HDL_2b-C amounts were positively correlated with HDL-C (r=0.721, p<0.001) and apo A-I (r=0.545, p<0.001) levels, but were not correlated with apo A-II. Plasma HDL_2a-C levels were positively correlated with HDL-C (r=0.638, p<0.001) concentrations, but were not correlated with apo A-II. The correlation coefficients with HDL-C and apo A-I were higher in HDL_2b-C levels than in HDL_2a-C levels. Plasma HDL_3a-C amounts were positively correlated with HDL-C (r=0.365, p<o.01), apo A-I (r=0.320, p<0.02) and apo A-II (r=0.470, p<0.001) levels. Plasma HDL_3b-C levels were positively correlated with apo A-I (r=0.287, p<0.02), apo A-II (r=0.530, p<0.001), apo C-II (r=0.420, p<0.001), apo C-III (r=0.344, p<0.01), and apo E (r=0.321, p<0.01) concentrations. Plasma HDL_3b-C levels were not correlated with HDL-C amounts. These results indicate the following. The concomitant changes of plasma HDL-C and apo A-I levels without apo A-II alteration suggest the alteration of HDL_2a and HDL_2b amounts, especially HDL_2b. Changes in HDL-C, apo A-I and apo A-II levels in the same direction reflect the alteration of HDL_3a amounts. HDL_3b might be heterogeneous because the plasma HDL_3b-C level was positively correlated with many kinds of apoprotein amounts. It was therefore concluded that the changes in HDL subfractions could be estimated by the measurement of plasma HDL-C and apoproteins.

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In order to elucidate the atherogenicity of diabetes mellitus (DM), we examined the incidence of coronary artery disease (CAD) and the characteristics of lipoprotein abnromalities in patients with heterozygous familial hypercholesterolemia (FH) accompanied with DM or impaired glucose tolerance (IGT). Fifteen patients (10%) out of 150 patients with FH over 40 years old were accompanied with DM and 27 patients (18%) by IGT. The incidence of CAD was high (43%) in the FH group without DM or IGT, as we had already reported. However, the combination of DM or IGT with FH was associated with a further increase in CAD incidence up to 80% and 59%, respectively. In addition, the incidence of myocardial infarctions was remarkably higher (67%) in the DM group compared with that in the non-DM/IGT group (19%) and that in the IGT group (30%). The CAD extent score in FH patients with CAD was higher in the DM group and in the IGT group than in the non-DM/IGT group. The incidence of lesions in the distal coronary arteries was significantly higher in the DM group than in the non-DM/IGT group, while there was no difference in the prevalence of proximal and middle lesions among the three groups.
Serum triglycerides levels were significantly higher in the DM group and the IGT group than in the normal group, while total cholesterol levels were not significantly different. When lipoproteins were analyzed by polyacrylamide gel electrophoresis, the frequency of midband appearance, which implies an increase of remnant lipoproteins, was significantly higher in the DM group and in the IGT group (DM: IGT: normal =87%: 72%: 29%). An ultracentrifugation analysis of the lipoproteins revealed that the intermediate density lipoprotein cholesterol was increased in the DM and IGT group. This data suggests that remnant lipoproteins, in addition to a high concentration of LDL in FH patients with DM and IGT, may accelerate coronary atherosclerosis in patients with FH.

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We evaluated an assay method for remnant-like lipoproteins (RLP) using an immunoaffinity gel mixture of apo B-100 and apo AI monoclonal antibodies. RLP was expressed in terms of a cholesterol value.
Ten items in the serum including serum cholesterol, triglycerides, apolipoproteins (AI, AII, B, CII, CIII, and E), RLP and Lp (a) were tested via statistical multivariate analysis. The statistical analysis showed that Lp (a) was independent of other serum lipids and apolipoproteins, and RLP was like as a character of remnant lipoproteins.
We observed the relationship within RLP or Lp (a) levels and the number of diseased vessels of stenosis in 176 coronary artery diseases (CAD) group. Lp (a) and RLP elevated in proportion to the number of diseased vessels of stenosis. The results indicated that a raised serum Lp (a) was a risk factor for CAD. However, the result on RLP was not significantly, it may note discrepancy because of smaller patient in frequency caused by increased RLP rather than increased Lp (a).
RLP levels were significantly high in the null-type apo (a) isoform. Although we detected Lp (a) in the RLP fraction, the Lp (a) was regarded as a free-type apo (a) with low-molecule isoproteins.

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We examined the characteristics of lipoproteins in PAN (puromycin aminonucleoside)-induced nephrotic rats. The TRL (triglyceride-rich lipoproteins), IDL, LDL and HDL were all detected in nephrotic rats as prominent peaks by HPLC (high-performance liquid chromatography), while only HDL was dominant in the control rats. The retention time of each fraction in the nephrotic rats was short compared to that in the controls, indicating that the particle size of the lipoproteins became larger. The total lipoprotein concentration in the nephrotic rats was 9.4-fold higher than that of the controls and particularly, the increase in LDL was greatest. The chemical composition of each lipoprotein isolated by sequential ultracentrifugation was also altered in the nephrotic rats. The percentage of protein was significantly decreased in all fractions suggesting that the lipoprotein density is reduced.
Serum apo A-I and B was increased 8.5- and 13-fold, respectively, but apo A-IV was reduced by 56% in the nephrotic rats. The SDS-gel patterns showed abundant apo B_L in the TRL of the nephrotic rats, whereas apo B_H was dominant in the TRL of the control rats. Additionally, nephrotic HDL₂ contained markedly increased apo A-I and significantly decreased apo A-IV and apo E compared to the control HDL_L.

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Urinary excretion of albumin, apo A-I, and apo A-IV were quantitated in PAN (puromycin aminonucleoside)-induced nephrotic rats. Urinary albumin excretion was significantly correlated with the serum cholesterol concentration (r=0.777, p<0.01), although there was no negative correlation between the serum albumin and cholesterol concentrations. On the other hand, the renal clearance value of apo A-I was markedly lower than that of the albumin or apo A-IV. In addition, there was a positive correlation in the clearance values between the apo A-IV and albumin. This observation suggests that apo A-IV is more readily filtered through a glomerular basement membrane than apo A-I, whereas the molecular weight of apo A-IV is greater than apo A-I. This may be associated with the different forms of the serum of the two apolipoproteins.
The immunohistochemical findings showed that both apo A-I and apo A-IV were localized within the renal tubular cells, while apo B was absent in the control kidney. In the nephrotic kidney, on the other hand, apo A-I and apo A-IV were aggregated in the tubular lumen and apo B was present in the glomeruli. These observations confirmed that apo A-I and apo A-IV were readily filtered through the glomeruli while apo B continued to remain in the glomeruli even in the nephrotic kidney.
The present study revealed that apo A-IV was excreted into the urine in the nephrotic model, leading to a reduction in its serum level, as well as in the albumin.

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We have studied the effect of Nipuradilol (Nip), a nitro-based β-blocker, on the proliferative changes of cultured vascular smooth muscle cells (VSMC). Nip had a direct inhibitory effect on the proliferation of VSMC grown in the presence of 10% FCS through the substantial supression of DNA synthesis. This inhibitory effect of Nip was accompanied by an increase in the cyclic-GMP content of VSMC, but not by an inhibition of cellular Na⁺-H⁺ antiport. These results suggest that Nip directly inhibits VSMC proliferation, presumably via an activation of the cellular cyclic-GMP system.

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Hypercholesterolemia is associated with an increased incidence of vascular complications, and Lipoprotein (a) (Lp (a)) is known to appear in high levels in patients with ischemic heart disease. Recently, nicotinic acid was reported as a drug for reducing the serum levels of Lp (a). In order to assess the actual degree of activation of the coagulation and fibrinolytic systems in patients with high levels of Lp (a).
We investigated the effects of niceritrol on plasma lipid, Lp (a) and the molecular markers of the coagulation system. Niceritrol (750-1, 500mg/day) was administered to 50 patients (thirty-two women and 18 men, aged 38-85 years) suffering from hypercholesterolemia with a plasma concentration of total lipoprotein (a) greater than 20mg/dl. The meann concentration of total cholesterol and lipoprotein. (a) were significantly decreased after treatment. At the same time, TAT also significantly decreased. This study suggested that niceritrol may prevent a hypercoagulable state by improving the high levels of Lp (a).

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Following the administration of Dai-Saiko-To (D-ext), New Zealand white (NZW) rabbit aortas were studied to determine the drug's effect on atherosclerosis induced by a ration high in cholesterol. Group A: D-ext administration (1, 000mg/kg body weight/day, Tsumura, Tokyo) for 1 or 2 years after providing feed containing 1.5% cholesterol for 3 months; Group B (control): received a normal diet (CR-1, CLEA JAPAN, INC., Tokyo) for 1 or 2 years after participating in the same atherogenic diet. Aortas were processed to carry out pathological and immunohistochemical analyses, and clarify distribution of collagen fibers, smooth muscle cells and macrophages.
The immunohistochemical studies found each type of collagen fiber to be distributed in the thickened intima of the NZW aorta. Several patterns of localization and distribution were classified. Scattered and random distribution of collagen fibers was more noticeable in group A than in group B. A number of anti-macrophage antigen positive foam cells were present in the lesions, and anti-muscle antigen positive SMC was also present. Group A showed a lower score of volume fraction and a different distribution of collagen fibers than did group B. Decreased smooth muscle cells and macrophages were found in the group A lesions.
In conclusion, groups A and B showed a different distribution of collagen fibers. These findings suggest that D-ext may have anti-atherosclerosis with hypolipidemic effects and a decreased collagen volume fraction.

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We investigated the effects of stress loading on the plasma levels of L-arginine using 13-week-old SHR and WKY rats. There was no significant difference in the L-arginine plasma levels in the resting groups of the SHR and WKY rats. A significant decrease in the L-arginine level was found in the SHR rats after stress loading. However, there was no change in L-arginine plasma levels between the stress group and the resting group of the WKY rats. Furthermore, we injected adrenaline or noradrenaline intraperitoneally to investigate the effects of catecholamines on the L-arginine plasma levels. Adrenaline, as well as noradrenaline, reduced the plasma levels of L-arginine in the SHR rats, whereas there was no significant change in the WKY rats. These findings indicate that there is an impairment of L-arginine metabolism in the SHR rats, and furthermore catecholamines such as adrenaline and noradrenaline play an important role in the change of plasma L-arginine levels after stress loading in the SHR rats.

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