Abstract:Aim To explore the changes of plasma tissue plasminogen activator (tPA), plasminogen activator inhibitor (PAI) activity,collagen degradation and osteopontin gene expression during vascular restenosis development. Methods The activities of tPA and PAI were measured by tPA and PAI kits, Northern blotting was used to detect osteopontin gene expression. Results The activity of tPA increased at 3 d after de-endothelization, and peaked at 7 d , the level of tPA increased from 296.1±120.2 IU/L (control group) to 856.2±195.3 IU/L (7 d). The results of hydroxyproline concentration showed that the collagen degradation increased at 3 d and peaked at 7 d after de-endothelialization, about 1.6 times compared with the control. Osteopontin gene expression was remarkably induced by de-endothelization, the peak expression was at 3 d after operation, and was about 5 times comparing with the control, then osteopontin gene expression decreased and returned to the control level at 14 d after operation. Conclusions Osteopontin, collagen turnover and tPA take part in the process of vascular remodeling during vascular restenosis development.

Abstract:Aim In order to find out the mechanism that macrophage colony-stimulating factor protects monocytes/macrophages from oxidative injury. Methods We used macrophage colong-stimulating factor(MCSF)-riched L929 cell conditioned medium (L929-CM) to investigate the effect of MCSF on glutathione peroxidase (GPx) gene expression in RAW264.7 cells applying enzyme activity determination and reverse transcription polymerase chain reaction (RT-PCR) technique. Results It showed that MCSF could improve selenium-dependent glutathione peroxidase (SeGPx) and non-selenium-dependent glutathione peroxidase (non-SeGPx) activity in RAW264.7 cells. MCSF could also increase plasma glutathione peroxidase (PLGPx) mRNA expression in the cells. However, there was no induction of phosphalipid hydroperoxide glutathione peroxidase (PHGPx) expression by MCSF. Conclusion MCSF might protect monocytes / macrophages from oxidative injury through improving antioxidant enzymes activities and gene expression.

Abstract:Aim To observe the effect of cyclosporin A( a inhibitor of calcineurin). On cardioprotection induced by ischemia preconditioning (IPC) and explore the role of calcineurin (CaN) signal pathway in IPC. Methods The model of ischemia /reperfusion (I/R) was produced in isolated rat heart. The cardic functions and the activity of myocardium calcineurin were mersured. Results It was found that IPC apparently attenuated the inhibition of cardic function induced by I/R. Compared with I/R group, in IPC group coronary perfusion flow(CPF),+LVdp/dt max and -LVdp/dt max decreased by 39%(P<0.01),33%(P<0.01) and 52%(P<0.01) respectively. Myocardial calcium content decreased by 21%(P<0.01). However CsA, the inhibitor of CaN, can conteract the cardioprotection effect of IPC. In addition, the activity of cardiac calcineurin was activated by cardiac I/R, compared with control group, the activity of CaN increased by 1.9 folds; ischemia preconditoning alone activated the activity of cardiac calcineurin and increased by 2.3 folds (P<0.01) compared with control group. Before ischemia preconditioning administration of CsA completely blocked the activation of calcineurin stimulated by IPC. Compared with IPC group, its activity decreased by 75%(P<0.01). Conclusion The results suggest that IPC-induced cardioprotective efffects are mediated by calcineurin pathway.

Abstract:Aim To study the effect of phosphalipids on the cholesterol efflux from rat macrophages mediated by HDL 3. Methods Measure the cholesterol content, cellular phospholipid content, and the balance between free cholesterol and cholesteryl ester when phosphatidylcholine (PC) or sphingomyelin (SPM) was added to the mediun. Results The cholesterol content changed from 79.95 μg/plate to 42.79, 37.16 and 31.53 in HDL 3, HDL 3+PC and HDL 3+SPM group respectively. The cellular phosphorous content in PC (PC-p) were 13.95 and 16.28 μg/plate in HDL 3 and HDL 3+PC group respectively. The cellular phosphorous content in SPM (SPM-p) were 5.03 and 7.01 μg/plate in HDL 3 and HDL 3+SPM group respectively. After macrophages were incubated with BSA, PC and SPM alone, the cellular cholesterol content were 75.30, 74.65 and 73.09μg/plate respectively and the ratio of free cholesterol to total cholesterol were 59.42%, 56.95% and 64.77% respectively. Conclusion PC and SPM couldn't mediate directly cellular cholesterol efflux, but they could enhance cellular cholesterol efflux from macrophages mediated by HDL 3, and the ability of SPM was stronger than PC. SPM could induce cholesteryl ester convert into free cholesterol. In macrophages and PC could induce free cholesterol convert into cholesteryl ester.

Abstract:Aim To study the mechanism of cholesterol efflux from rat peritoneal macrophages mediated by high density lipoprotein-3(HDL 3). Methods Modification of HDL 3 by N-acetylimidazole blocked interaction between HDL and its cellular receptor. FITC labeled HDL 3 were used to observed the cellular metabolic process of HDL 3. Results BSA (control group) mediated 2.9% cellular cholesterol efflux from the cells. In HDL 3 group and N-acetylimidazole-HDL 3 group,they were 40.7% and 8.7% respectively. After incubation of macrophages with FITC-HDL 3 at 37℃for 3 h, the cell-endocytic fluorescence strength (FS) was 65.0% of the cell-associated FS. When the cells were further incubated with blank media at 37℃for 2 h, 78.4% of the cell-endocytic FS was released into the media. Both the cell-endocytic FS and the cell-released FS were mainly in trichloroacetic acid precepitable form. Conclusions The cellular cholesterol efflux from macrophages mediated by HDL 3 was HDL receptor-dependent. The possible mechanism could be that macrophages internalized HDL 3 by HDL receptor. HDL 3 picked up cellular cholesterol and was resecreted out of cells by a retroendocytic pathway without taking a celluar lysosomal phathway.

Abstract:Aim To evaluate the effects of lecithin phospholipid liposomes on arterial narrowing after balloon angioplasty in the atherosclerosis rabbits. Methods 50 New Zealand rabbits were divided into observation group (high lipid food plus lecithin phospholipid liposomes), operation group ( no lipid food ), nonoperation group (high lipid food only ) , high lipid group (high lipid food only) and control group ( no lipid food ). The rabbits of the observation group, operation group and high lipid group were underwent balloon angioplasty in the left common iliac artery. The observation group was given lecithin phospholipid liposomes liquids. Results It had indicated the rabbits left iliac arterial lumen diameter was larger, its wall was thicker and its cholesterol concentration was smaller in the observation group than that of the high lipid group (P< 0.05). Aortic arterial plaque area in the observation group was less than that of the high lipid group (P<0.001). In the observation group, higher HDLC, lower VLDLC, LDLC, TC and TG concentration can be observed than that of the high lipid group (P<0.05). Conclusion Lecithin phospholipid liposomes could effectively reduce arterial narrowing in the atherosclerosis rabbits.

Abstract:Aim It has been proved in our previous work that destruction of arcuate nucleus could induce early atherosclerosis .In order to further research into the influence of hypothalamic arcuate nucleus on the development of atheroscerosis, this study was to investigated whether the transplantation of cell suspension of arcuate nucleus into the destroyed nucleus would act on the recovery of atherosclerosis. Methods Eighteen new born Wistar rats injected with monosodium glutamate(MSG)4 g/kg hypodermically once every other day for 5 d were used as induced atherosclerosis model. After surviving for 30 d, six animals sacrificed with their aorta taken serve as control group Ⅰ. The other 12 animals were equally divided into experiment group and control group Ⅱ. The experimental group were transplanted with 5 μL cell suspension (1×10 15 /L)of arcuate nucleus from 14 d embryo and control groupⅡ were given equal volume of normal saline. After surviving for another 30 d, the aorta of these animals were made ultrathin section and investigated under electromicroscope. Results In control group Ⅰ(arcuate nucleus damaged by MSG for 30 d), microvillous projections of endothelial cells were observed on the luminal surface and the nuclei of the endothelial cells became twisted and irregular, but without thickening of subendothelial tissue. In control group Ⅱ(arcuate nucleus damaged by MSG for 60 d), degeneration of endothelial cells could be seen and some endothelial cells had fallen off. The subendothelial tissue was evidently thickened with a few collagnous fibers, vesicles of various size and macrophage or smooth muscle cells migrated from blood and tunica media through the ruptured elastic intima, indicating characteristic changes of early atherosclerosis. In the experimental group (transplanted with embryonic arcuate nucleus), the endothelial cells remained intact, and connected tightly with subendothelial tissue, occasionally twisted nucleus could be seen. Conclusions This experiment indicate that transplanted arcuate nucleus in the destroyed nucleus has notably made the animal recovery from atherosclerosis and thereby confirms that hypothalamic arcuate nucleus has influence on development and/or control of atherosclerosis.

Abstract:Aim To investigate the effect of estradiol on inhibition of neointimal proliferation after rat carotid artery balloon injury. Methods Eight-ten week-old S-D rats were divided into intact control group (n=7), gonadectomized control group (n=7) and estradiol (n=7,gonadectomization)group in each sex. Left carotid artery was not injured with 2.0F PTCA balloon until estradiol had been injected for three days. Rats were killed after injury two weeks later. Neointimal areas, ratios of intimal areas and media areas were measured with computer. Results Neointimal areas and ratios of inttimal areas and media areas in male in estradiol group were significantly less than those in intact control group (allP<0.01), and in gonadectomized control group (allP<0.05). Those in female ,in estradiol group were less than those in godectomized control group evidently (allP<0.01),were also similar to those in intact control group (all P>0.05). Conclusion Estradiol inhibited neointimal proliferation after the gonadectomized rat carotid artery balloon injury.

Abstract:Aim To study size of low density lipoprotein (LDL) particle in patients with coronary artery disease (CHD).Methods Plasma LDL in 37 CHD patients and 26 control subjects were analyzed by 2%～16% non-denaturing polyacrylamide gradient gels. Results The CHD patients had significantly less particle diameters than control subjects(25.71±0.66 nm vs. 26.41±0.95 nm, respectively;P<0.01). The distribution of LDL subfraction pattern was significantly difference between two groups (P<0.05). LDL particle diameter was found negatively correlated with plasma triglycerides (r=-0.29,P<0.05) and apoB (r=-0.25,P<0.05) level, while positively correlated with plasma HDLC level(r=0.28,P<0.05). Free cholesterol to protein ratio of LDL in pattern B was found less than that in pattern A (1.02±0.45 vs. 1.59±1.21,P<0.05), meanwhile a significantly positive correlation was also found between LDL particle diameter and this ratio (r=0.31,P<0.05).Conclusion Small, density pattern B LDL subfraction may be a risk factor for atherosclerosis. Plasma triglyceride may be a factor in regulation of LDL subfraction particle diameter.

Abstract:Aim To investigate the effects of hypoxic or ischemic preconditioning on cardiomyocytes. Methods In the hypoxia/reoxygenation (H/R) model of cultured neonatal rat cardi omyocytes, and the ischemia/reperfusion (I/S) model of the isolated or in situ rat hearts, the present study observes the effects of PC on H/R or I/R injury on cardiomyocytes. The infarct size, cell viability, LDH release and the content of MDA were measured. Results Hypoxia PC attenuated H/R injuries on cardiomyocytes. On the model of cultured neonatal rat cardiomyocytes, compared with the cardiomyocytes unpreconditioned, the number of viable cell and the SOD content were increased (P<0.01), the LDH release and the MDA content were decreased (P<0.01) in preconditioned group. In isolated or in situ rat hearts, ischemic PC decreased the injuries to cardiomyocytes. The coronary artery effusion or plasma LDH levels, tissue MDA contents, the infarct sizes and arrhythmia during occlusion or reperfusion were greatly decreased in preconditioned myocardium after a long time I/R than those in the unpreconditioned (P< 0.01). Conclusions Cultured neonatal rat cardiomyocytes, isolated and in situ rat hearts have PC phenomenon. PC can obviously protect cultured neonatal rat cardiomyocytes, isolated or in situ rat heart from H/R or I/R injuries.

Abstract:Aim To investigate the effects of tea pigment on experimental atherosclerosis in hypercholesterolemia rabbits.Methods According to serum cholesterol and triglyceride level twenty-four rabbits were divided into control group fed with high cholesterol diet, low dose tea pigments group fed with high cholesterol diet and 32 μg/g·d tea pigments orally, high dose tea pigments group fed with high cholesterol diet and 96 μg/g·d tea pigment orally. After 8 weeks, all animals were killed to determine the serum lipids, plasma endothelin, the percent of thoracic aorta inner surface covered by plaque and the ratio of intimal to medial cross-sectional areas in ascendent aorta. Results Tea pigments had no effect on lipid level within the experimental doses.The plasma endothelin level was reduced in high dose tea pigments group (P<0.05). The aorta plaque areas in both tea pigment groups were significantly lower than that of control group (P<0.05). Conclusions It is suggested that tea pigments could protect the formation of aorta plaque and reduce the level of endothelin in plasma in the hypercholesterolemia rabbits.

Abstract:Aim To study nitric oxide (NO) variances after vascular endothial cell were impacted by low density lipoprotein (LDL) and high density lipoprotein (HDL). Methods Concentrations of NO in the cultured medium were detected in 2 h, 6 h, 12 h and 24 h after the addition of LDL, HDL and both of them respectively in the guinea pig vasular endothial cell. Results LDL could obviously decrease the NO synthesized by vasular endothial cell with dose depentent (P<0.01)and HDL could arise it (P<0.01), LDL mixed with three levels of HDL expressed the same effection as LDL alone (P>0.05). There was no difference in four time's group (P>0.05). Conclusions NO synthesized by vasular endothial cell will be restrainted by LDL and arisen by HDL but couldn't antagonist the former's.

Abstract:Aim To evaluate the effectiveness of nifedipine and enalaprilat on collagen proliferation after balloon injury in a rabbit model. Methods Thirty-two healthy male New Zealand white rabbits were divided into control group, nifedipine group and enalaprilat group. Conventional balloon angioplasty in the right common iliac artery was done. Arterial bloods were taken before angioplasty, 30 minuets and 2 weeks after angioplasty for analyzing plasma AngⅡ. For histology, Masson's staining was performed two weeks later. All the specimens were analyzed using a computerized imaging analysis system. Results In the control group, plasma AngⅡ elevated from 2.70±0.31 g/L to 2.83±0.18 g/L 30 min after angioplasty (P<0.05), and returned to 2.50±0.26 g/L two weeks later (P<0.05). There was no significant AngⅡdifferences between the control and the nifedipine groups. Enalaprilat significantly inhibited plasma AngⅡ elevation 30 min after angioplasty. Histological computerized imaging analysis showed significant collagen proliferation after angioplasty (P<0.01). There was a significant decrease of collagen proliferation in the enalaprilat group (P<0.01). Conclusions Significant vascular wall collagen proliferation was observed after angioplasty. Enalaprilat inhibited vascular wall collagen proliferation, thus may be effective in the prevention of resrenosis after successful pecutaneous transluminal coronary angioplasty.

Abstract:Aim To investigate the effect of high cholesterol chow on high density lipoprotein (HDL) receptors in hepatic plasma membranes with 125 I-labeled HDL 3 as ligands. Methods The hepatic plasma membranes were purified by density gradient ultracentrifugation from rabbits fed with high cholesterol chow and rabbits fed with normal chow. Apolipoprotein E deficient HDL 3 was isolated from plasma of normally fed rabbits by density gradient ultracentrifugation, and labeled with 125 I by ICl method. Radioreceptor assays were carried out by incubation of the purified plasma membranes with labeled and unlabeled HDL. Results HDL receptors on hepatic plasma membranes of rabbits fed with high cholesterol chow and normal chow have an average Kd of 8.06±3.10 mg/L and 9.27±3.54 mg/L. There is no statistical difference of Kd between the two groups. But HDL receptors on hepatic plasma membranes of rabbits fed with high cholesterol chow have an higher value of Bmax than those with normal chow (2.46±0.72 mg/g vs 1.18±0.48 mg/g,P<0.001). Conclusions The high cholesterol chow can up-regulate the HDL receptors, and increase the HDL receptor activity on hepatic plasma membranes of rabbits.

Abstract:Aim To investigate the effect and significance of glucose and insulin on phospholipase A 2 (PLA 2) activities of vascular smooth muscle cells(VSMC). Methods VSMCs in rats were incubated with the DEME which had different concentration glucose or/and insulin for 72 h PLA 2 activities were detected with [ 3 H]-Oleate radioactivity(cpm). Results PLA 2 activities increased with high concentration of glucose or/and insulin and there were dose-dependent relationship. Conclusion The increased PLA 2 activities were associated with atherosclerosis in diabetes, so treatment with PLA 2 inhibitor could prevent the pathological progress of athcrosclerosis in diabetes.

Abstract:Aim To investigate the role of reninangiotensin system (RAS) in the cause of fibrinolytic dysfunction. Methods 28 male Wistar rats were randomly divided into four groups: LNNA group: Wistar rats wre administered by intraperinoneol injection of LNNA (15 mg/kg everyday) to induce hypertensive model for 5 weeks; Losartan group and Enalapril group: the hypertensvie model were induced as LNNA group, and treated with losartan (10 mg/kg everyday) or enalapril (10 mg/kg everyday) by gavage from second to fifth week; 4) Control group: treated with normal saline and tap water instead of LNNA and losartan or enalapril in the same procedure. The activity changes of PAI1 and tPA both in plasma and in isolated vessls incubation were mearsured by spectrophotometric assay. Results Significant fibrinolytic dysfunction was found in the LNNA rats, and this dysfunction was markedly improved by the treatment with losartan or enalapril; Compared with the control group, the ability of PAI1 release in isolated vessels of LNNA rats was significantly increased (P<0.01). In the losartan and enalapriltreated group, the baseline levels and thrombininduced release of PAI1 in isolated vessels were reduced by 19%46% and 25%50% respectively (P<0.05), and there is no statistical difference between the two treatment groups. When induced by 10.0 kIU/L thrombin, the tPA release in isolated vessels of LNNA rats were 32% lower than that of controls (P<0.05), and this decline was not improved by the treatment with losartan and enalapril. Conclusions The regulation of RAS on fibrinolysis system is to accelerate the release of PAI1, which is mediated by Angiotensin Ⅱ.

Abstract:Aim and Methods Endothelin 1 (Et-1) is a potent vasoconstriction peptide which was firstly isolated from the conditioned medium of porcine aortic endothelial cells. Hypoxia can induce Et-1 gene expression in rat lung tissue and pulmonary artery. In order to assess the role of Et-1 in processes of pulmonary vasoconstriction and pulmonary vessel remodeling induced by hypoxia, the effects of ET-1 on contraction of pulmonary artery in rat and proliferation of pulmonary arterial smooth muscle cells in cultured of rabbit are investigated. Results ET-1 at concentrations ranged from 1× -9 to 12×10 9 mol/L caused-depended contration of vessel rings of rat pulmonary artery (r=0.935,P<0.05). When rabbit pulmonary arterial smooth muscle cells were cultured in the presence of 0.5% fetal calf serum (FCS), ET-1 at concentrations ranged from 1×10 11 to 1×10 -8 mol/L also stimulated 3 H-thymidine and 3 H- leucine incorporation in confluent quiescent monolayers in a dose-dependent manner (r=0.756 and 0.840, respectively), with EC50 being 10.87 nmol/L and 8.54 nmol/L. Conclusion Endothelin-1 may play a certain role in the hypoxic pulmonary hypertension.

Abstract:Aim To explore the relationship between human cytomegalovirus (hCMV)infection and coronary heart disease (CHD). Methods Peripheral blood specimens from 56 CHD patients and 42 controls were detected by PCR for the presence of hCMV nucleic acid in white blood cell using the hCMV pp71 gene primer pair, and the levels of total cholesterol (TC), triglyceride (TG), apolipoprotein A (Apo A), apolipoprotein B (Apo B) in serum were analyzed simultaneously. Results With the hCMV pp71 gene primer, hCMV nucleic acid was found in 58.93% of the CHD patients and in 28.57% of controls, the difference is significant (P<0.01). The positive rate of hCMV in acute myocardial infarction (AMI) and unstable angina pectoris (UAP) patients is higher than that in the other types of CHD patients(77.27% vs 47.06%,P<0.05). For the CHD patients, no significant difference in the levels of serum TC, TG, Apo A and Apo B was found between hCMV positive ones and hCMV negative ones. Conclusion hCMV infection is relevant to CHD, and may be regard as an risk factor for CHD; CHD patients with hCMV are apt to suffer from AMI and UAP.

Abstract:Aim To investigate the relationships between polymorphism of candidate gene and carotid artery arteriosclerosis in essential hypertension (EH) patients, the frequencies of C1166 allele of angiotensin II type 1 receptor (AT 1R) gene was determined in normotensives and hypertensives Methods Blood pressure (Bp), body mass index (BMI), fasting serum glucose (Glu), serum total cholesterol (TC) and triglyceride (TG) were measured in 86 normotensives and 120 hypertensives. Intimal-medial thickness (IMT), diameter (D) and I/D of common carotid artery in 32 normotensives and 68 hypertensives were determined. Genomic DNA was extracted from peripheral blood leukocytes by standard method. Polymerase chain reaction (PCR) combined with restriction enzyme digestion was used to detect the polymorphism. Results The frequency of AC genotype and C1166 allele of AT 1R gene of EH patients were higher than that of control (P<0.01 andP<0.05), EH subjects with AC genotype had increased common carotid artery IMT and I/D than those with AA genotype (P<0.05 andP<0.01). Conclusions A1166C polymorphism of AT 1R gene were associated with EH in Chinese population. C1166 allele of AT 1R gene may play a role in arteriosclerosis of hypertension.

Abstract:Aim This study was to clarify whether insulin resistance and hyperinsulinemia are causative factors in the cerebral infarction. Methods Fourtyone consecutive patients with cerebral infarction, who don`t suffer from hypertension, coronary heart disease, diabetes or obesity, were classified into two groups-atherthrombotic infarction (n=25) and lacunar infarction (n=16)-based on clinical findings, brain imaging. Serum insulin, oral glucose tolerance test and lipid analyses were performed. Data were compared with control subjects(n=15). Results After the oral glucose tolerance test, the serum insulin level and the 2 h blood sugar concentration of the atherithrombotic cerebral infarction patients are both higher than those of the contrast group with remarkable statistic significance (P<0.01). The serum insulin level of the lacunar infarction patients is alse higher than that of the contrast group (P<0.05). The levels of serum insulin, insulin/glucose (I/G) were significantly higher in both groups of consecutive patients. Conclusions Insulin resistace and hyperinsulinemia may separately be one of the risk factors for cerebral infarction.

Abstract:Aim The paper was done to evaluate the relations between intima-media thickness (IMT) of common carotid artery (CCA) and plaque in the internal carotid artery (ICA) and bifurcations (CBs). Methods B-mode ultrasound examination of carotid arteries was per formed in 91 subjects. B-mode ultrasound examination include measurement of CCA-IMT and the sites of plaque in the ICA and CBs. Results The results showed that the prevalence of plaque increased from the lowest to the highest quintile of IMT(linear trend:P<0.01). The mean IMT was lower in subjects without plaques than in subjects with plaques (0.64±0.12 mm vs 0.83±0.16 mm,P<0.01), there was an increasing trend for IMT with the severity of plaque. Conclusion Increases in IMT as measured in the CCA are clearly related to atherosclerotic plaque in the ICA and CBs.

Abstract:Aim To explore the correlation between CGG triplet repeat polymorphism on the 5' non-coding region of very low density lipoprotein receptor (VLDLR) gene and coronary heart disease (CHD) in Chinese Han nationality, 235 subjects with no blood links in Hubei region, including 75 cases with CHD and 160 healthy controls were studied. Methods Polymerase chain reaction (PCR)-denature polyacrylamide gel electrophoresis-silver stain technique was employed to determine the CGG triplet repeat polymorphism of VLDLR gene. Results The Chinese Han nationality in Hubei region has VLDLR gene polymorphism, 4 alleles with 5, 8, 9, 11 CGG triplet repeats and 8 genotypes with 5/5, 5/8, 8/8, 8/9, 9/9, 5/9, 8/11 and 5/11 were detected. There were no statistically significant differences in VLDLR gene allele and genotype frequencies between CHD and normal controls (P>0.05). Conclusions There is VLDLR gene polymorphism in the Han Chinese in Hubei region and such polymorphism has ethnic difference. CGG triplet repeat polymorphism of VLDLR gene has no correlation with CHD. It is not an independent risk factor