Plasma nitrite/nitrate level is inversely correlated with plasma low-density lipoprotein cholesterol level

BACKGROUND

Plasma nitrite/nitrate (NOx) is a stable end product of the vasodilator nitric oxide (NO). However, there are few reports about plasma NOx levels in humans.

HYPOTHESIS

The purpose of this study was to assess the availability of plasma NOx for evaluating basal endogenously-synthesized or endothelium-derived NO, and to examine whether NOx levels are lowered in patients with coronary artery disease (CAD) or its risk factors.

METHODS

Plasma NOx levels were measured using an automated system based on the Griess reaction. NOx levels for a 24-h period reproducibly became lowest at 6 A.M. in restricted healthy volunteers, and became stable in inpatient volunteers at 6 A.M. within 4 days after admission.

RESULTS

Based on these findings, NOx levels at 6 A.M. in inpatients can be considered as the basal levels. In 40 inpatients suspected of CAD (28 men, 12 women; mean age 60 +/- 11 years), the basal levels of NOx were not related to CAD and its risk factors, except for hypercholesterolemia. The NOx level of patients with hypercholesterolemia was significantly lower than that of patients with normal cholesterol (n = 16,34 +/- 16 mumol/l vs. n = 24, 49 +/- 23 mumol/l, p < 0.03). Furthermore, the NOx levels correlated negatively with the total cholesterol and low-density lipoprotein cholesterol levels (r = -0.40, p < 0.01; r = -0.47, p < 0.003, respectively), but not with other lipid fraction levels.

CONCLUSION

The results suggest that the quantity of basal endothelium-derived NO synthesis may be decreased in the presence of hypercholesterolemia.

Syntheses and biological evaluations of alpha-D-mannosyl [60]fullerenols

[60]Fullerenols carrying mono- and bis-alpha-D-mannosyl linkages on the surface were prepared via a [3+2]-cycloaddition reaction between 2-azidoethyl alpha-D-mannoside and C(60) followed by polyhydroxylation with aqueous NaOH. Their biological activity was evaluated in terms of binding affinity to lectins by hemagglutination assay and surface plasmon resonance. [60]Fullerenols without the mannosyl linkage caused aggregation of erythrocytes and binding to a beta-D-galactopyranoside specific lectin (RCA(120)). In contrast, mono- and bis-mannosyl fullerenols were found to decrease the activity for both aggregating erythrocytes and binding to RCA(120), and mono-mannosyl fullerenols turned to binding to alpha-D-mannose specific lectin (Con A).

Chlamydia pneumoniae infection and accelerated development of coronary artery disease in patients with chronic renal failure

AIMS

This study examined the relationship between Chlamydia pneumoniae (C. pneumoniae) infection and the accelerated development of coronary artery disease (CAD) in patients with chronic renal failure (CRF).

METHODS

Two-hundred and fourteen patients undergoing coronary angiography, including 67 controls and 147 patients with CAD (97 without CRF and 50 with CRF), were enrolled in this study. Anti-C. pneumoniae specific IgG and IgA antibodies were measured using an enzyme-linked immunosorbent assay (ELISA).

RESULTS

Coronary artery disease (expressed as CAD score) was more severe in patients with than without CRF (14.9 +/- 6.0 vs. 11.3 +/- 6.0, p < 0.01). Seropositive rates of IgG and IgA antibodies against C. pneumoniae were higher in all CAD patients than in the controls (76.2% vs. 44.8%, p < 0.001 for IgG; 59.9% vs. 40.3%, p < 0.01 for IgA). In both CAD subgroups, IgG seropositive rates were similarly elevated (82.0% and 73.2% vs. 44.8% for control, p < 0.001, respectively), whereas those of IgA were significantly elevated only in CAD with CRF (68.0% vs. 55.7% for control, p < 0.01). The mean antibody index of IgG was elevated in all CAD patients compared with the controls (1.9 +/- 1.0 vs. 1.3 +/- 0.9, p < 0.0001), but that of IgA was not (1.5 +/- 1.0 vs. 1.2 +/- 0.9). Levels of IgG were elevated in all patients with CAD compared with the control (2.4 +/- 1.1 and 1.8 +/- 1.0 vs. 1.3 +/- 0.9, p < 0.001 and p < 0.001, respectively), whereas those of IgA were elevated only in CAD with CRF (1.8 +/- 1.1 vs. 1.2 +/- 0.9, p < 0.05). Stepwise logistic regression analysis revealed that the elevated IgG antibody index was an independent risk factor for CAD regardless of CRF (odds ratios 1.9, 1.8, and 2.3), whereas the IgA index was a risk factor only in CAD with CRF (odds ratio 1.7).

CONCLUSIONS

Chlamydia pneumoniae infection may be related to the accelerated CAD in patients with CRF, which was specifically suggested by an elevated IgA level. In other words, the prevalence of active C. pneumoniae infection is higher in patients with CAD and CRF than that in those with CAD without CRF.

Acute-phase proteins and Chlamydia pneumoniae infection: which one is more important in acute coronary syndrome?

Elevated levels of acute-phase proteins, a systemic marker for inflammation, predict coronary events; Chlamydia pneumoniae (C. pneumoniae) infection is associated with coronary atherosclerosis. The present study investigated whether inflammation or infection is involved in the pathogenesis of acute coronary syndrome (ACS) and which one has the more important role. The study group comprised 49 patients with angiographically diagnosed ACS, 48 cases of chronic coronary heart disease (CCHD), and 44 subjects with a normal coronary profile. The levels of serum C-reactive protein (CRP), fibrinogen and anti-C. pneumoniae IgG antibody were measured. The IgG antibody against C. pneumoniae was higher in the ACS and CCHD groups compared with the control group after adjusting for age and gender. The levels of CRP and fibrinogen were significantly increased in patients with ACS compared with controls and CCHD patients. Multiple stepwise logistic regression analysis revealed that C. pneumoniae IgG antibody is an independent risk factor for both ACS and CCHD (odds ratio 2.3 and 2.1, respectively), but the CRP level is a risk factor only for ACS (odds ratio 6.9). The inflammatory response, as indicated by acute-phase proteins, especially CRP, rather than C. pneumoniae infection, may contribute more to the clinical course of ACS.

Modification of low density lipoprotein potentiates its inhibitory effect on catecholamine secretion in cultured bovine adrenal medullary cells

Low density lipoprotein (LDL) and lipoprotein(a) suppress catecholamine secretion in cultured adrenal medullary cells. Modification of LDL by oxidation or acetylation potentiates various atherogenic actions of LDL. In the present study, we investigated whether the modification of LDL influences catecholamine secretion in cultured bovine adrenal medullary cells. The exposure of LDL to CuSO4 caused a time-dependent oxidation of LDL. Maximal oxidation of LDL was observed after exposure to CuSO4 for 24 h. Native LDL inhibited catecholamine secretion induced by carbachol to 68.5% of control. Oxidized LDL caused further inhibition of carbachol-evoked secretion to 37.6% of control. Acetylated LDL inhibited it to 41.0% of control. There was a good correlation between the extent of LDL oxidation and the inhibition of catecholamine secretion. These results suggest that oxidation or acetylation of LDL augments its inhibitory effect on the secretion of catecholamines. Since catecholamines are a risk factor of atherosclerosis, the inhibitory effect by such modified LDL may be a mechanism inhibiting atherosclerotic progression.

Atherogenic lipoproteins inhibit catecholamine secretion in cultured bovine adrenal medullary cells

The effects of lipoproteins on ion channel-mediated catecholamine secretion were investigated in cultured bovine adrenal medullary cells. Low density lipoprotein (LDL: 20-80 mg/dl) and lipoprotein(a) [Lp(a); 10-80 mg/dl] inhibited catecholamine secretion induced by carbachol, an activator of nicotinic acetylcholine receptor-ion channels. LDL and Lp(a) suppressed carbachol-induced 22Na+ influx as well as 45Ca2+ influx in a concentration-dependent manner similar to that of catecholamine secretion. The inhibition of catecholamine secretion by Lp(a) was not overcome by increasing the concentration of carbachol. On the other hand, high density lipoprotein (HDL; < 150 mg/dl) had no effect on 22Na+ influx, 45Ca2+ influx, and catecholamine secretion. Like LDL and Lp(a), a synthetic peptide homologous to human plasma apolipoprotein B (apoB), apoB fragment(3358-3372)-amide (3-60 microM), attenuated 22Na+ influx, 45Ca2+ influx, and catecholamine secretion caused by carbachol. The apoB fragment also suppressed 22Na+ influx induced by veratridine (an activator of voltage-dependent Na+ channels) and 45Ca2+ influx induced by 56 mM K+ (an indirect activator of voltage-dependent Ca2+ channels). These findings suggest that atherogenic lipoproteins such as LDL and Lp(a) suppress catecholamine secretion by interfering with Na+ influx through nicotinic acetylcholine receptor-ion channels, in which apoB, a structural component common to both LDL and Lp(a), plays an important role. The inhibition by atherogenic lipoproteins of catecholamine secretion may influence the progression of atherosclerosis induced by these lipoproteins.

Enhanced macrophage uptake of lipoprotein(a) after Ca2+-induced aggregate-formation

We tested the hypothesis that aggregated lipoprotein(a) [Lp(a)] is avidly taken up by macrophages. Lp(a) was isolated by sequential centrifugations and gel chromatography from a patient with high plasma levels of Lp(a) who was being treated with low density lipoprotein (LDL)-apheresis. Aggregated Lp(a) was prepared by mixing native Lp(a) with 2.5 mmol/L CaCl2, and 54% of the 125I-Lp(a) aggregated after interacting with CaCl2. The binding and degradation of aggregated Lp(a) in macrophages were 4.6- and 4.7-fold higher than those of native Lp(a), respectively. An excess amount of LDL did not inhibit either increase. Cholesterol esterification in macrophages was markedly stimulated by aggregated Lp(a), and macrophages were transformed into foam cells. Cytochalasin B, a phagocytosis inhibitor, strongly inhibited the degradation and cholesterol esterification (78 and 83%, respectively). These findings suggested that aggregation may be partially involved in Lp(a) accumulation, thereby contributing to the acceleration of atherosclerosis.

Simvastatin increases plasma NO2- and NO3- levels in patients with hypercholesterolemia

In this study, plasma NO2- and NO3- (NOx-) levels were studied after lowering cholesterol with simvastatin in 26 outpatients with hypercholesterolemia (male, 9; female, 17; mean age, 59 +/- 12 years; cholesterol level > 220 mg/dl). Simvastatin (5 mg) was orally administered once daily, and blood samples were collected before, and after 4 and 12 weeks of treatment. Total, very-low-density lipoprotein (VLDL), and low-density lipoprotein (LDL) cholesterol were lowered (total, 254 +/- 44 mg/dl to 209 +/- 34 mg/dl; VLDL, 48 mg/dl [5-126 mg/dl] to 34 mg/dl [10-67 mg/dl]; LDL, 171 +/- 41 mg/dl to 133 +/- 37 mg/dl), but high-density lipoprotein (HDL) cholesterol was elevated (33 +/- 9.5 mg/dl to 39 +/- 11 mg/dl) at 12 weeks after starting simvastatin. Although the effects of simvastatin on the lipid levels nearly reached their maximum levels at 4 weeks, NOx- was elevated in a linear fashion with simvastatin (before; 8 +/- 17 mumol/l, at 12 weeks; 57 +/- 32 mumol/l). The % changes in the NOx- correlated directly with those in HDL-cholesterol at 12 weeks (P < 0.002) but not with other lipoprotein cholesterol fractions. These results suggest that simvastatin lowers cholesterol levels and elevates HDL while increasing the plasma NOx- levels.

Effects of systolic anterior motion of the mitral valve on haemodynamics. Evaluation by a direct method

We evaluated the effects of systolic anterior motion systolic anterior motion of the mitral valve on cardiac haemodynamics. Seven adult mongrel dogs in which systolic anterior motion-septal contact was observed after dobutamine administration were used. To exclude the effects of left ventricular function and morphology, a stone removal basket catheter was placed in the left ventricular outflow tract, and haemodynamics were compared with the basket closed and opened. The basket was opened five times in three dogs not showing systolic anterior motion-septal contact, but the basket itself did not effect the haemodynamics. In the seven dogs that showed systolic anterior motion-septal contact without left ventricular hypertrophy, the basket was opened a total of 33 times in the presence of various degrees of systolic anterior motion-septal contact. After opening the basket, systolic anterior motion was reduced echocardiographically, and significant (P<0.01) changes were observed in the left ventricle-aorta pressure gradient (from 68 +/- 22 to 25 +/- 15 mm Hg), the systolic ejection period (from 146 +/- 19 to 135 +/- 16 ms), and the stroke volume (SV; from 9.4 +/- 2.9 to 10.1 +/- 3.3 ml). After basket inflation, aortic pressure and aortic flow waveforms changed but the peak pressure and flow velocity did not. The temporal distribution of left ventricular ejection also definitely changed after the basket was opened. No changes were observed in the peak dp/dt, peak negative dp/dt, time constant, left ventricular end-diastolic pressure, or left atrial pressure. These observations in this animal model of systolic anterior motion without left ventricular hypertrophy suggest that: (1) there is no potential for generation of an intra-cavity gradient in the absence of systolic anterior motion of the mitral valve, so that (2) systolic anterior motion narrowed the left ventricular outflow tract and, consequently, produced the systolic ejection period, and affected the left ventricular ejection dynamics, and that (3) the basket catheter is useful because it allows these assessments in the same heart with a nearly fixed left ventricular contractility, at least in our animal model.

Increased susceptibility of angiographically smooth left anterior descending coronary artery to an impairment of vasoresponse to acetylcholine, and the relation between impaired vasoresponse and low-density lipoprotein cholesterol level

In the present study, we demonstrated that the angiographically smooth LAD is more susceptible than the LC to an impairment of vasoresponse to acetylcholine, suggesting the more severe endothelial dysfunction in the LAD. We also showed that levels of LDL play a partial but important role on endothelial dysfunction.

Immunochemically detectable lipid-free apo(a) in plasma and in human atherosclerotic lesions

Although Lp(a) is an independent risk factor for cardiovascular diseases in humans, the precise pathogenetic mechanisms are still unknown. We have shown that Lp(a) accumulates in human atherosclerotic lesions, and some particles undergo oxidation. Since, following agarose electrophoresis of both plaque extracts and plasma, a region close to the origin immunostained intensely for apo(a) but was lipid-free, we sought to identify whether such samples contained lipid-free apo(a), as previously reported to occur in plaque extracts. Immunochemically identifiable apo(a) was found following density-gradient ultracentrifugation both in the 1.05 < d < 1.09 and the d > 1.21 density fraction from both plasma and plaque extracts. However, because in a competitive binding RIA, displacement curves of apo(a) in plasma and the d > 1.21 were not parallel, it is premature to ascribe a relative amount of total apo(a) to this fraction. Whereas apo(a) immunoblots of SDS-PAGE under reducing conditions of the d > 1.21 fraction of a plaque extract with high apo(a) content showed high molecular weight bands consistent with apo(a) isoforms, the corresponding d > 1.21 fraction showed multiple low molecular weight bands characteristic of fragmentation. Since the d > 1.21 of arterial extracts contained all the material immunostaining for apo(a) migrating towards the cathode, characteristic of immunoglobulins (IgG), we asked whether fragments of apo(a) might have associated with human IgG both in plasma and tissue extracts, or whether our anti-apo(a) reacted with epitopes on human IgG. Immunoblotting with our anti-apo(a) of samples of plasma and plaque extracts run on agarose electrophoresis or SDS-PAGE further demonstrated intense staining of multiple bands in the molecular weight range of human IgG. Furthermore, a fraction of plasma and tissue extracts that bound to a protein G affinity column demonstrated immunostaining for apo(a) and was in the size range of IgG. Although one polyclonal anti-apo(a) provided by another laboratory showed the same findings as our antibody, two other polyclonal anti-apo(a) failed to demonstrate immunostaining of human IgG, either on agarose electrophoresis or SDS-PAGE. We speculate that the Lp(a) immunogen used to prepare our anti-apo(a) may have undergone modest oxidation, thus exposing epitopes not normally expressed on apo(a) in native Lp(a). Either antibodies to these epitopes could be recognizing apo(a) fragments, possibly released during oxidation, which are then covalently bound to IgG, or oxidation of apo(a) creates epitopes on apo(a) that are homologous with IgG, thereby leading to cross-reactivity with IgG.(ABSTRACT TRUNCATED AT 400 WORDS)

Partial characterization of lipoproteins containing apo[a] in human atherosclerotic lesions

Previously we quantified the amounts of immunoreactive apo[a] found in human atherosclerotic lesions extracted sequentially with phosphate-buffered saline (PBS) and guanidine hydrochloride (GuHCl). In this study we have attempted to characterize lipoproteins containing apo[a] in such PBS and GuHCl fractions, obtained from autopsy samples, in order to eventually determine their structure-function relationships critical for evaluating the mechanisms that make them atherogenic. Apo[a] in the PBS extracts migrated slightly ahead of plasma Lp[a] on agarose electrophoresis. Although apo[a] in extracts showed the same isoforms as in plasma in SDS-PAGE, it was also highly fragmented. When a d < 1.10 g/ml ultracentrifugation fraction of the PBS extract was subjected to gel filtration, a major part of the immunoreactive apo[a] in this fraction co-isolated with plasma Lp[a]. When the Lp[a]-sized fraction was further separated by density gradient ultracentrifugation, a subpopulation was isolated containing apo[a] in the 1.06 < d < 1.08 g/ml density range that was free of lesion-derived low density lipoprotein (LDL) (A-LDL). This fraction contained immunoreactive apo[a] and apoB, had a total cholesterol to protein ratio of about 1, and demonstrated increases in fluorescence (360 ex/430 em) and conjugated dienes that were even greater than values obtained for the corresponding A-LDL sample. The void volume fraction following gel exclusion chromatography of the d < 1.10 g/ml fractions contained both apo[a] and apoB that comigrated on nondenaturing PAGE, suggesting that they were present on the same particle. Apo[a] in GuHCl extracts comigrated with plasma Lp[a] on agarose electrophoresis and contained apo[a] isoforms of similar molecular weights as those found in corresponding plasma samples. When the GuHCl extract was subjected directly to gel filtration in the presence of 6 M GuHCl, two included peaks of apo[a] immunoreactivity were present, one eluting slightly ahead of plasma Lp[a], the other slightly ahead of plasma LDL. Collectively, these data indicate that apo[a] is present in human atherosclerotic lesions in forms resembling intact but oxidized plasma Lp[a], as larger particles possibly representing Lp[a] complexed to itself or other plaque components, and as slightly smaller particles possibly representing degraded Lp[a].

Insoluble complex formation of lipoprotein (a) with low density lipoprotein in the presence of calcium ions

We investigated whether apolipoprotein B-containing lipoproteins could bind to the insoluble complexes of lipoprotein (a) (Lp(a)) induced by Ca2+. Lp(a), but not low density lipoprotein (LDL), very low density lipoprotein (VLDL), or high density lipoprotein3 (HDL3) formed insoluble complexes at physiologic Ca2+ concentrations. Desialylation of Lp(a) dramatically decreased the ability of Lp(a) to aggregate, suggesting that sialic acids on Lp(a) were responsible for forming Ca2+ cross-bridges. Since a reduction of only 30% of the sialic acids on Lp(a) inhibited Ca(2+)-induced complex formation, it appears that only a small percentage of sialic acids on Lp(a) is involved in Ca(2+)-induced cross-bridging of Lp(a) particles. To determine whether other lipoproteins would complex to Lp(a) in the insoluble complexes, we mixed Lp(a) with LDL, VLDL, or HDL3 in the presence of Ca2+. Although both LDL and VLDL bound to the Lp(a) in the insoluble complexes, HDL3 not only did not bind, but it also prevented Lp(a) from forming insoluble complexes. LDL bound to Lp(a) in the insoluble complexes in a concentration-dependent manner, eventually reaching saturation at a molar ratio of 5:4 (LDL to Lp(a)). The interaction between LDL and Lp(a) appeared to be ionic, since increases in the positive charge on LDL by desialylation increased this interaction, whereas decreases in positive charge on LDL reduced this interaction. At higher Ca2+ concentrations, the binding of acetyl LDL to Lp(a) in the insoluble complexes was greater than that of LDL. Since more Ca2+ was required for concentration-dependent saturation of acetyl LDL binding, it is likely that Ca2+ cross-bridging was responsible for this binding. Thus, LDL, especially its modified forms, could contribute to the formation of insoluble complex of Lp(a) with Ca2+ in atherosclerotic lesions and help explain its preferential accumulation there.

Heparin-releasable platelet factor 4 in patients with coronary artery disease

Recently, platelet factor 4 (PF4) release by heparin (heparin-releasable PF4) has been examined as a useful marker of the interaction between the substances liberated from circulating platelets and the vascular endothelium. We compared the plasma levels of PF4 and beta-thromboglobulin (beta-TG) after intravenous heparin injection in patients with coronary artery disease (CAD) and normal control subjects. We also studied the effects of low-dose aspirin (81 mg/day) on the plasma level of heparin-releasable PF4 in the CAD patients. Blood samples were obtained before and 5 min after the intravenous injection of heparin (1,000 IU) from 23 patients with CAD and 15 normal control subjects. Although the plasma beta-TG level remained unchanged after heparin injection, the plasma PF4 level markedly increased in both groups. There was a significant difference in plasma PF4 levels at 5 min after heparin injection between the CAD group (100.1 +/- 38.1) and the control group (61.0 +/- 24.0) (p less than 0.01). The PF4/beta-TG ratio after heparin injection was also higher in the CAD group than in the control group (p less than 0.01). There was a correlation between the PF4/beta-TG ratio after heparin and the Gensini CAD score, which defines the severity of coronary atherosclerosis (r = 0.489, n = 23, p less than 0.01). Low-dose aspirin was administered to 11 CAD patients for 246.0 +/- 28.8 days. Blood samples for the assay of PF4 and beta-TG were obtained as stated above, and platelet aggregation, thromboxane B2 (TxB2), and 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) levels were also measured before and during aspirin administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Sustained-release nifedipine (nifedipine-L) suppresses plasma thromboxane B2 and 6-keto prostaglandin F1 alpha in both young male smokers and nonsmokers

Sustained-release nifedipine (nifedipine-L) (40 mg twice a day) was administered orally to healthy young adult male smokers and nonsmokers for 10 days, and its effects on platelet aggregation, beta-thromboglobulin and platelet factor 4 levels, and plasma thromboxane B2 (TxB2) and 6-ketoprostaglandin F1 alpha (6-Keto-PGF1 alpha) concentrations were studied. The plasma nifedipine-L concentration in smokers (46.0 +/- 7.4 ng/ml) was significantly lower than that in nonsmokers (88.2 +/- 1.2 ng/ml). Nifedipine-L did not affect platelet aggregation induced by adenosine diphosphate, collagen, or epinephrine in either smokers or nonsmokers. The plasma beta-thromboglobulin level on the tenth day of nifedipine-L administration in nonsmokers was lower than that in smokers, but there were no significant differences either with or without nifedipine-L or between nonsmokers and smokers. Nifedipine-L had no effect on the concentration of platelet factor 4 in either smokers or nonsmokers. On the other hand, nifedipine-L significantly decreased the plasma TxB2 and 6-keto-PGF1 alpha concentrations in both smokers and nonsmokers. Thus we concluded that nifedipine-L suppressed the production of plasma TxB2 from platelets and also subsequently suppressed the production of 6-keto-PGF1 alpha and that this action was not affected by cigarette smoking.

Comparison of serum lipid values in variant angina pectoris and fixed coronary artery disease with normal subjects

Lipid and apolipoprotein (apo) levels in patients with variant angina were examined and compared with patients with coronary artery disease (CAD) and normal subjects (control). Cholesterol and triglyceride levels in plasma, lipoprotein fractions and several apolipoproteins were measured in 108 men (90 of whom had undergone coronary angiography): 22 had variant angina, 56 had fixed CAD (effort angina and old myocardial infarction) and 30 were normal subjects. Patients with variant angina showed more severe atherosclerotic lesions than the control group, but less severe lesions than the patients with fixed CAD. In comparison with lipid and apolipoprotein, high density lipoprotein cholesterol, apo AI and apo AII decreased significantly in control, variant angina and fixed CAD groups, respectively. Additionally, stepwise discriminant analysis revealed that apo AI was the best discriminator among the 3 groups or between variant angina or fixed CAD and the control group. Variant angina and fixed CAD patients could be discriminated from the control subjects by an apo AI level of 135 and 126 mg/dl, with 71% (p less than 0.025) and 73% (p less than 0.005) accuracy, respectively. By these criteria 77% of the patients with variant angina and 73% of the patients with fixed CAD were precisely discriminated. Discrimination between variant angina and fixed CAD patients, however, was not practical, even if the best discriminator was used. Thus, the apo AI level is useful in discriminating patients with variant angina and fixed CAD from normal subjects. Therefore, symptomatic patients with low apo AI levels should be aggressively examined.

[The analysis of the result of the medical examination of inhabitants in the Honjoh area--the relationship between the abnormality in the electrocardiogram and blood pressure, age]

Blood pressure and electrocardiographic findings obtained from the medical screening of citizen (total 834) in Honjyo area, which was done in University of Occupational and Environmental Health Hospital from 1979 to 1983, were analysed. The findings of electrocardiograms (ECG) were classified according to Minnesota code. In this study, the prevalence of Hypertension, classified by the criteria of WHO, showed 12.2% in total, which was lesser than that of Japanese (23.1%). On the electrocardiographic findings, left ventricular hypertrophy and myocardial abnormalities in hypertensive group were significantly higher when compared to those of normotensive group. The ratio of abnormal ECG group was slightly higher than that of Japanese. Especially, the prevalences of arrhythmia and ST elevation were significantly higher than those of Japanese. And there were significant correlations between LVH and blood pressure, and between the abnormalities of conduction system and age. However, it is very difficult to conclude whether these findings are characteristic feature in Honjyo area or not. In order to clarify the characteristic features of cardiovascular systemic abnormalities in Honjyo area, the analysis of more cases would be needed.

Hypocholesterolemic effect of soybean protein in rats and mice after peptic digestion

Analyses of gastrointestinal contents of rats fed soybean protein isolate and casein showed that soybean protein was readily digested in the stomach but migrated slowly in the small intestine. The soluble fraction of the stomach contents of rats fed soybean protein was separated by gel-filtration on Sephadex G25 into large and small molecular fractions, the latter was not found in rats fed casein. The formation of low-molecular-weight peptides was pH dependent, and analogous peptides were produced by pepsin in vitro not only from soybean protein but also from casein. In rats the peptic digest of soybean protein was found to be as hypocholesterolemic as intact soybean protein. Meanwhile, the cholesterol-lowering action of the large molecular fraction of the peptic digest tended to be greater than that of the small molecular fraction in mice. These observations suggest a significant role of peptic digestion in the cholesterol-lowering action of soybean protein.