CEase activity in rat adipose tissue was determined using a micellar substrate. This substrate was found more suitable than a liposomal substrate in respect of K_m and V_max. The activity was enhanced by c-AMP, ATP, Mg²⁺, and A-Kinase from bovine hearts. A nine-week duration of OV-X significantly decreased serum estradiol level (30%) and CEase activity (41%) in the parametrial adipose tissue. In contrast, orchiectomy failed to exert such an effect on the epididymal adipose tissue. The content of c-AMP in the parametrial adipose tissue was unaltered due to OV-X, but the A-Kinase activity was attenuated in parallel to the change in the CEase activity. It is suggested that the change in CEase activity due to OV-X is reflected by the A-Kinase activity.

View full abstract

Atherogenic risk factors in 923 school age children were examined over a five-year period (age 7 to age 12). Correlations between observation 5 years apart were 0.569 for serum cholesterol, 0.547 for HDL-cholesterol, 0.471 for atherogenic index and 0.502 for systolic blood pressure. Height (0.870), weight (0.852) and body mass index (0.836) showed higher correlations than 4 factors above. Separate analyses in males and females of the two correlations in Fig. 1 showed no difference in serum CHL between sexes while in atherogenic index the slope in males was greater in females, suggesting hormonal influence at the higher age. Ninety-five percentile values for cholesterol at age 7 and 12 were 191 and 210mg/dl. Percentile ranks were divided into quintiles. Fourty-six percent of children initially in the highest quintile remained in the same rank while 48% of children in the lowest quintile were there again 5 years later. Preliminary analysis of answers to questionnaire pertinent to dietary habbits, life style, diseases and family histories, indicated less influence on serum cholesterol of dietary habbits and life styles during school age. These results suggest the significance of the investigation of serum cholesterol and other risk factors at early ages for taking preventive measure to children at high risks.

View full abstract

The effects of prostacyclin (PGI₂) and stable derivative of prostacyclin (Isocarbacyclin) on junctional transport of fluorescein dextran (FD) through cultured porcine arterial endothelial cells were investigated. These PGI₂'s inhibited the transcellular transport dose-dependently. After the elimination of PGI₂, its inhibitory effect persisted for at least 1hr. A good connection was found between increase of cAMP and the potency of inhibition. Increase of CAMP after PGI₂ treatment seemed to be involved in the inhibition of FD transport.

View full abstract

TPA level were determined with an enzymelinked immunoabsorbent assay in plasma of 49 patients with cerebral infarction, 6 with cerebral hemorrhage and 24 healthy controls. Infarct patients were assigned, according to the arterial lesions responsible for stroke, to cortical and perforating arterial group (CI and PI group). TPA levels in 25 specimens in PI and 6 in CI group within 4 weeks since the onset were 9.77±3.54ng/ml and 12.86±2.62ng/ml respectively. Plasma TPA levels in subsequent period after 4 weeks from the onset were 13.58±3.49ng/ml in 9 specimens obtained from CI, 8.14±2.56ng/ml in 17 from PI and 8.14±2.95ng/ml in 6 from hemorrhagic group, the level in CI group was significantly higher compared with the value of PI or hemorrhagic group.
The values throughout the period of this trial were 13.29±3.09ng/ml in 15 specimens from CI and 9.11±3.24ng/ml in 42 from PI group, the level in CI group was significantly higher than the value in PI group. TPA level was directly proportional to β-thromboglobulin. These results demonstrate clearly important role of TPA in cerebral infarction originated from ischemic lesion in cortical arterial region. In conclusion, determination of plasma TPA is available for clinical observation of atherothrombotic disorders in cerebral infarction.

View full abstract

The frequency of ischemic heart disease is higher in Japanese-Americans as compared to native residents of Japan. To further elucidate this point, we compared the concentration of serum lipids and apolipoproteins (Apo) between 301 Japanese residents of the U. S. and 136 Japanese who reside in Japan.
The levels of serum cholesterol and triglyceride were higher in the Japanese-Americans, while HDL cholesterol levels were higher in the residents of Japan. But unexpectedly Apo A-I, A-II, B and E concentrations in the two populations resembled each other.
Thus it was suggested that the differences in lipoprotein composition between two populations might affect the pathogenesis of ischemic heart disease.

View full abstract

Single dosage of probucol and combined dosage of probucol and γ-oryzanol were administered to thirteen patients with hypercholesterolemia to study their effects on serum lipid, apoprotein and lipoprotein particle size.
In comparison to the single dosage of probucol, a combined dosage with γ-oryzanol showed a significant decline in total cholesterol (TC) and apo B as well as a considerable rise in HDL-C/TC ratio and apo A-I/apo B ratio. The combined dosage was believed to be effective in preventing atherosclerosis.
Formation of large HDL particles was observed in patients with coronary heart disease (CHD). Probucol administration was conversely found to produce the formation of small HDL particles. Although the low HDL-C state was observed in probucol administration as well as in patients with CHD, the size of HDL particles was different. Probucol administration seems to have a favorable effect on preventing atherosclerosis in terms of HDL particle size in spite of inducing a decrease in HDL-C level.

View full abstract

We studied the long-term effect of CDCA and a competitive HMG-CoA reductase inhibitor (CS-514) on clinical symptoms and sterol metabolism in three patients from one family with CTX. Proband (case 1, 36 y.o., male) manifested marked tendon xanthomas and mild dementia with obvious encephalographic abnormalities. He was treated for two years with CDCA (0.8g/day) and further for one year with combination of CS-514 (10mg/day) and CDCA (0.8g/day). His two siblings (case 2 and 3, 31 and 29 y.o., females) showed tendon xanthomas and cerebellar ataxia or pyramidal sign complicated with hyperthyroidism. They were given CDCA (0.4g/day) for a year and further for one year CS-514 singly.
Plasma cholestanol levels before treatment were approximately 3mg/dl in all cases which were twenty times of controls. In proband, plasma cholestanol was reduced from 3.12mg/dl to 1.96mg/dl by CDCA and further to 0.92mg/dl by combination therapy with CS-514. Whereas plasma cholesterol was slightly increased by CDCA and reduced by combination therapy. Administration of CDCA also resulted in substantial reduction of plasma cholestanol in his siblings but single treatment with CS-514 caused no reduction of plasma cholestanol. These findings suggest that plasma cholestanol lowered by the increase of bile acid pool supplemented with CDCA, which may enhance feed back mechanism of 7α-hydroxylase, and still more decreased by combination with the inhibition of sterol synthesis.
Clinically, in case 1, his xanthomas regressed remarkably and the mental detardation improved associated with normalization of electroencephalographic abnormalities after treatment with CDCA and combination with CS-514. In his sisters, tendon xanthomas also regressed and neurologic symptoms improved after treatment with CDCA.
We conclude that combination therapy with CDCA and CS-514 is effective for the correction of biochemical abnormalities much more than with single treatment of CDCA.

View full abstract

Current evidences suggest that calcium may play a pathogenic role in atherosclerosis. In cholesterolfed rabbits, calcium channel blockers such as nifedipine, verapamil and diltiazem have been demonstrated to exert antiatherogenic effects without reducing the diet-induced hypercholesterolemia. In the present study, rat aortic smooth muscle cells (SMC) were used to study the effects of verapamil, diltiazem and nicorandil on cellular interactions with human low density lipoprotein (LDL). Specific bindings of ¹²⁵I-LDL to SMC were not significantly changed by these drugs. Specific internalization were significantly increased by verapamil and diltiazem at concentration of 10^-4M compared to control. Only verapamil of three agents decreased significantly specific degradation of ¹²⁵I-LDL at concentration of 10^-4M. Nicorandil, 10^-8 to 10^-4M, did not affect catabolism of ¹²⁵I-LDL in SMC. These findings indicated that these drugs affect the intracellular catabolism of LDL differently in SMC.

View full abstract

We observed macrophage-derived foam cells separated from rabbit atherosclerotic lesions by a transmission electron microscope. Most of them are heavily lipid-laden, with a peripheral nucleus and have many microvilli in contrast to rabbit blood monocytes, which rarely have microvilli.
Macrophage-derived foam cells produce superoxide (O₂^-) when stimulated by phorbol 12-myristate 13-acetate.

View full abstract

An injectable emulsion of docosahexaenoic acid (DHA) was prepared. One hundred ml of emulsion contained 10g of 93%-pure 1, 2, 3-tridocosahexa-enoyl-glycerol, 1.2g of 93%-pure 2-docosahexa-enoyl-phosphatidyl-choline as an emulsifier and 2.5g of glycerol. Thirty ml of the DHA emulsion was injected into 3 rabbits on days 1 and 4 of the study. Blood was taken on days 0 and 7. The percent of DHA in total phospholipids of platelets was significantly increased from 0.46mol% to 3.66mol%. The percent of DHA in total phospholipids in red blood cell membranes was significantly increased from 0.23mol% to 1.52mol%. Blood lipids were unchanged except that free fatty acids significantly decreased from 0.32mEq/l to 0.06mEq/l. On day 8, after arachidonic acid (2mg/kg) injection from ear vein none of DHA-treated rabbits died, while all of four DHA-untreated control rabbits died within several minutes after arachidonic acid injection (χ² test, p<0.01). The DHA emulsion may be useful for patients having immediate risk of thrombosis or for those who need DHA but cannot take it orally.

View full abstract

Macrophages derived foam cells and platelets are found in many lesions of atherosclerosis. The object of the study is to evaluate the effect of platelets' secretory products on foam cell formation of macrophages. Firstly, we got two kinds of platelet free supernatants, which one is prepared from platelets rich plasma frozen and thawed three times (PSPα), another one from thrombin activated platelets (PSPβ). We studied whether these supernatants and other platelets' secretory products (PDGF, STA₂, and SEROTONIN) enhanced macrophages lipid storage or not by using a microscale enzymatic assay system. PSPα, PSPβ and PDGF enhanced esterified cholesterol accumulation. We supposed that platelets contributed to the lipid storage of macrophages in developing atherosclerosis.

View full abstract

The ODS rat is a strain lacking in Vitamin C (VC) biosynthesis. The effects of marginal VC deficiency on serum lipids and aortic endothelial cell of ODS rats were studied. The marginal VC deficient ODS rat group (Group 1, n=14) was fed a VC deficient diet and administered water which contained VC (1mg/ml) once a week orally to prevent scurvy. The control ODS rat group (Group 2, n=14) was given the same VC deficient diet along with the same dosage of VC diluted in water (1mg/ml). This group received the VC daily. The Wister-Shionogi rat group (Group 3, n=3) which can synthesize VC by itself was used to refer to blood VC concentration. The following results were obtained;
1) Blood VC concentration was 0.24±0.05, 0.79±0.12 and 1.74±0.84mg/dl respectively in Group 1 (n=4), Group 2 (n=4) and Group 3 (n=3).
2) Serum triglyceride and very low density lipoprotein were lower in Group 1 than in Group 2. Total cholesterol, free cholesterol, cholesterol ester and phospholipid in serum were not significantly changed in either group. No hyperlipidemia was seen in Group 1.
3) Serum lipid peroxides were higher in Group 1 than in Group 2.
4) Transmission electron micrograph showed decreased number of mitochondria in cytoplasm and hair-like projections on the endothelial cell surface, and macrophage migration into the widening subendothelial space of aortic endothelium in Group 1.
Endothelial cell injury is known to be an important factor in the early stage of atherosclerotic progression. We conclude that VC deficiency most likely is an initiator of atherosclerosis.

View full abstract

In order to understand the relationship between elastin and atherosclerosis the investigation was undertaken using aorta by measuring amounts of aortic elastin, amino acid analysis of extracted elastin, and elastin binding lipids. Hog aortic elastin was extracted using for several kinds of methods (collagenase, cyanogen bromide (BrCN), NaOH and formic acid methods), and it was considered that the most purified elastin could be obtained by the BrCN method according to the amino acid analysis. The contents of elastin binding lipids showed different levels in each method. In BrCN method the ratio of cholesterol ester and phospholipids were the highest, while the total amounts of lipid levels were the lowest among the four methods. In the analysis of human aorta with atherosclerosis, contents of elastin in the BrCN method increased, and it was considered that the degenerated collagen or pseudoelastin were contaminated in the elastin fraction according to the amino acid analysis. Elastin binding lipid, especially cholesterol ester and phospholipid fraction, increased in the atherosclerotic aorta. These results suggest that the quantitative and qualitative changes of aortic elastin and elastin binding lipids were strongly related to the atherosclerotic development.

View full abstract

Anti-atherogenic effect of elastase and magnesium, especially these effects on the serum lipids and metals, was examined. Five groups of rabbits: a control group, two groups on a 1% cholesterol diet with and without porcine pancreatic elastase (Eisai Co., Ltd., 5mg i. m./kg B. W./day), and the other two groups on a 1% cholesterol diet containing an additional 1% magnesium with and without porcine pancreatic elastase (5mg i. m./kg B. W./day), were studied for 4 months.
Treatment with elastase and/or magnesium suppressed the elevations of serum cholesterol and triglyceride levels induced by the cholesterol diet. In particular, the combined use of elastase and magnesium exhibited the significant suppressive effect. In rabbits given the cholesterol diet containing magnesium, a remarkable increase in magnesium concentrations and a moderate decrease in calcium concentrations were observed in serum. Furthermore, there was a negative correlation between calcium and magnesium (p<0.001) in serum. These results may suggest the antagonistic action of magnesium toward calcium. In erythrocytes, the competition between calcium and magnesium was also observed and its competitive action was more effective in the combined use of elastase and magnesium. In rabbits treated with elastase, copper concentrations in serum increased markedly. A negative correlation between copper and triglyceride (p<0.001) implies that this increase in copper concentrations may lead into a decrease in serum triglyceride levels.
Since the anti-atherogenic effect of elastase has been reported in the previous paper, we here discuss the beneficial effects of magnesium as hereunder. The increase of serum magnesium is correlated directly or indirectly to the following changes: (a) a lowering of elevated serum triglyceride levels; (b) a decrease in serum calcium concentrations; (c) an increase in magnesium concentrations in erythrocytes. Further study on such a role of magnesium is under way.

View full abstract

The erythrocytes and plasma from 3 homozygous and 2 heterozygous cases of a family with genetic hypobetalipoproteinemia were examined biochemically and morphologically. In contrast with lowered cholesterol content in plasma, the erythrocyte membrane cholesterol was slightly increased in the patients. In both the erythrocytes and plasma from the homozygotes, an increased ratio of the sphingomyelin/phosphatidylcholine content and a decreased content of linoleic acid in the total lipids were observed. Slight tendency of such changes was also observed on the specimen from the heterozygotes. In the erythrocytes from the homozygous cases, decreased membrane fluidity was detected, whereas no abnormality was found in the SDS-PAGE pattern of the membrane proteins, anion (sulfate) permeability through the membrane or ATP utilization and production. Typical acanthocytosis was observed on 6-13% of the erythrocyte population from the homozygotes and on 2-3% of those from the heterozygotes.

View full abstract

The calcium channel blockers, nifedipine and verapamil, has been shown to suppress atherogenesis in cholesterol-fed rabbits. In most of the studies, the degree of atherosclerosis was determined morphologically by staining the total aortic intima for lipid. The aim of the present study was to investigate the effect of drugs which decrease Ca⁺⁺ concentration in cytosol on receptor-mediated endocytosis of low density lipoprotein by cultured human skin fibroblasts and rat hepatoma cells (RHC). Fibroblasts and RHC were incubated with ₁₂₅I-LDL, unlabeled LDL and various concentration of drugs at 37°C. Specific saturable binding, internalization and degradation by fibroblasts and RHC of LDL were observed. Specific bindings of ¹²⁵I-LDL by fibroblasts were not significantly changed by verapamil (V) and nicorandil (N), but it was significantly increased by diltiazem (D) at concentration of 10^-4M compared to control. Specific internalizations were significantly increased by V and D at concentration of 10^-4M, but it was not changed by N. Only verapamil of three agents decreased significantly specific degradation of ¹²⁵I-LDL at concentration of 10^-4M. Specific binding and internalization of ¹²⁵I-LDL by RHC were similar to fibroblasts and were significantly increased by V and D at concentration of 10^-4M. But nicorandil at concentration of 10^-4M did not affect binding and internalization. Specific degradation of ¹²⁵I-LDL by RHC was significantly increased by N, but not by V and D. Our studies indicated that these drugs affect the intracellular metabolism of LDL differently in fibroblasts and RHC.

View full abstract

Since PTCA required less stress and shorter hospitalization; therefore, expansion of its application for elderly patients with coronary artery disease is being attempted. In this paper, we explicated the primary results and long-term outcome of PTCA in the elderly.
On 74 PTCAs, 14 patients were 65 years or older (mean 70.1±5.2 years). On angiography, elderly patients differed in the more frequent occurrence of three-vessel diease (29% vs. 8% in younger patients, p<0.05) and left ventricular dysfunction (21% vs. 2% in younger patients, p<0.005).
Clinical primary success was achieved in 86% (12/14 cases), vs. 95% (57/60 cases) in younger patients. Angiographic primary success was achieved in 88% (14/16 lesions) vs. 95% (78/82 lesions) in younger patients. Clinical success for unstable angina was achieved in 82%, vs. 88% in younger patients; for multiple dilatation, 100% vs. 93% in younger patients. There was no major complication in both groups. Repeat angioplasty success for restenosis was achieved in all cases of both groups. Clinical follow-up more than one year in whom PTCA was successful showed that symptomatic improvement was achieved in 89%, vs. 96% in younger patients. These data support the safety and clinical effectiveness of PTCA in elderly patients with coronary artery disease.

View full abstract

The purpose of the present study is to clarify the inhibitory effect of taurine on the elevation of cytoplasmic Ca²⁺ concentration ([Ca²⁺]i) in activated platelets. Using aequorin-loaded platelets activated with 1μM A23187 in normal subjects, [Ca²⁺]i was measured by a Platelet Ionized Calcium Aggregometer (Chrono-log). The elevation of [Ca²⁺]i in platelets activated with A23187 was significantly inhibited by the incubation with 1mM taurine for 10min. In order to elucidate the mechanism of this inhibitory effect of taurine, the aequorin-loaded platelets were pretreated with 5×10^-5M aspirin (ASA) and 10^-4M dibutyryl c-AMP (dbcAMP) before the incubation with 1mM taurine. The pretreatment with both of ASA and dbcAMP significantly inhibited [Ca²⁺]i in platelet activated with A23187 significantly. The elevation of [Ca²⁺]i in ASA-pretreated platelet activated with A23187 was further inhibited by the incubation with taurine, but in dbcAMP-pretreated platelet was not. These results suggest the possibility that the inhibitory mechanism of taurine on the elevation of [Ca²⁺]i in platelets activated with A23187 is not related to arachidonic metabolism. But it remains to be investigated wether the inhibition of taurine to platelet activation with A23187 is due to c-AMP-related mechanism or no related one.

View full abstract

Diurnal variations of human serum lipids and 3-hydroxy-3-methylglutaryl Coenzyme A (HMG CoA) reductase activity in peripheral blood mononuclear cells (PBMCs) was investigated in 6 healthy normolipidemic adult males. ΔSerum TG (post-prandial serum TG-fasting serum TG) and Δd<1.006 fruction TG (postprandial d<1.006 fruction TG-fasting d<1.006 fruction TG) correlated significantly with fasting serum TG and d<1.006 fruction TG levels. LDL-C levels significantly increased after high cholesterol diets, and HMG CoA reductase activity in PBMCs was inhibited 6%, but not significantly. HMG CoA reductase did not exhibit a diurnal rhythm in activity, not similar to enzyme in rat liver and intestine, unless a period of dietary equivalent lasting a few weeks.

View full abstract