Abstract:Aim Characterization of the structural and functional changes in low density lipoprotein (LDL) aftermodification with both malondialdehyde (MDA) and 4hydroxynonenal (HNE).Methods LDL was modified with both 40 mmol/L MDA and 6 mmol/L HNE. A rabbit antibody against this double modified LDL was produced by use of continuous LDL-coupled affinity chromatography. The antigenic structure properties of MDA-HNE-LDL (MH-LDL) was investigated with a competitive enzyme linked immunosorbent assay (ELISA ). The degradation of 123 I-MH-LDL by THP-l cells and mouse peritoneal macrophages were measured eparately to evaluate the biological significance of LDL modified with double aldehydes.Results The purified antibody against MH-LDL did not react with native LDL and acetyl LDL. However,MDA-LDL, HNE-LDL,and oxidized LDL showed a certain degree of competitive inhibitory effects to the binding of the antibody with MDA-HNE-LDL (70%, 33% and 21%, respectively). The degradation of 12:I-MH-LDL by THP-l cells (243 ± 53 μg/g cell protein) was similar to that of 125 I-oxidized LDL (233f35 ig/g cell protein) but lower than 125I-LDL (441± 16 μg/g cell protein). Both MH-LDL and acetyl LDL could competitively inhibit 125I-MH-LDL degradation by THP-l cells where as native LDL did not. In mouse peritoneal macrophages 125 I-MH-LDL was degraded as much as 10 times of 125I-LDL. When incubated with various amounts of antibody against MHLDL, 125I-MH-LDL degradation by macrophages differed from 18% to 223% of that in the absence of the antibody.Conclusion Antigenity of MH-LDL might primarily depended on the modification of MDA. The uptake of MH-LDL by cells would be mediated via scavenger receptor pathway.

Abstract:Aim To observe the induction of apoptosis in vascular smooth muscle cell (SAC) by the introduction of wild-type P53 gene and investigate the mechanism of inhibition for SMC proliferation by wild-type P53 gene.Methods A replication--deficient adenovirus vector encoding a wild-type P53,AdCMV P53,was constructed and trans feeted into the cultured rabbit aortic SMC.The cell cycle of SMC was analysed with flow cytometry. The 3H-thymidine incorporation assay was used to measure DNA synthesis in SAC. The apoptotic cells was determined by termmed deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and agarose gel electrophoresis.Results Introduction of wild-type P53 gene into SMC can arrest 77% of AdCMV P53--infected cells at GO/GI phases of the cell cycle, leading to inhibition of DNA synthesis. Overexpression of wild-type P53 induced apoptosis of cells infected with AdCMV P53 as detected by TUNEL and flow cytometry. Electrophoresis of genomic DNA showed internucleosomal fragments of DNA isolated from the AdCMV P53--infected SMC.Conclusion Wild-type P53 gene suppress SMC pro liferation by induction of apoptosis in SMC.

Abstract:Aim A large amount of literature reported that Larginine-nitric oxide (L-Arg--NO) pathway involVed in the formation and progression of atherosclerosis (As)induced by hypercholesterolemia. The purpose of this study is to determine the effects of L-arginine on the atherosclerotic plaque formation.Methods New Zealand white rabbits (n=144 ) were assigned to control group, nifedipine group,isosorbide dinitrate group, L-arginine group and hypercholesterolemic group, respectively. Experiment included a 90 days' treatment and 180 days' treatment.The percentage of atherosclerotic plaque covering aortic and coronary intima was measured.Results The atherosclerotic plaque area was reduced by feeding with L-arginine at l, 1. 5 and 2 g/kg in each day at this study. While in nifedipine treated groups and in isosorbide dinitrate treated groups, the plaque area gave higher values than L-arginine treated groups, but lower than those of hypercholesterolemic groups. The effects of L-arginine on antiatherosclerosis was more significant than nifedipine and isosorbide dinitrate.Conclusion L-arginine exerts strong antiatherosclerotic effect in experimental rabbit. Nifedipine and isosorbide dinitrate has the similar effect but with a slightly weaker action.

Abstract:Aim Platelet derived growth factor (PDGF) plays important roles in the development of atherosclerosis.In order to block the effects of PDGF, PDGF receptor binding domain was fused with the hepatitis B core antigen (HBcAg) to form a fusion protein. This fusion protein can be used as a vaccine for the prevention of atherosclerosis in animal models. In this paper we report only the cloning of the fusion protein gene. Methods The gene of PDGF receptor binding domain, a 13 iner peptide, ANFLVWEIVRKKP, with 2 linkers (for Ndel and EcoRI) was synthesized chemically and cloned into a vector PBS. The HBcAg gene was obtained with polymerase chain reaction (PCR)technique and fused with the 13 iner peptide gene-pBS at the EcoRI and BamHI sites. Results A DNA fragment of about 600 hp in size was obtained. DNA sequencing analysis showed that the sequence of the 13iner peptide gene and the reading frame of the fused gene were both correct. Conclusion The gene of the fusion protein of the 13 iner peptide with HBcAg was successfully cloned in the vector PBS.

Abstract:Aim The purpose of the study is to well understand expression of cyclin D in smooth muscle cells and its association with lipid peroxidation injury to endothelial cellls.Methods The lipid peroxidation injury to cultured endothelial cells was induced by diamide,then diamide stimulating endothelial cell-derived conditioned media were collected. After a 24-hour culture of smooth muscle cells exposed to various epithelial cell derived conditioned media, smooth muscle cells were collected, and used to immunocytochemistry stainning and proliferative test.Results Rabbit smooth muscle cells could express cyclin D, the reactant of immune reaction was mainly located in nuclei. The media conditioned by diamide stimulating endothelial cells induced stronger expression of cyclin D in smooth muscle cells (p<0. 01).Meanwhile the amount of 3H-TdR incorporation into DNA in smooth muscle cells induced by the media was obvious larger than that induced by normal endothelial cell derived conditioned media (p<0. 01).Conclusion The proliferation of smooth muscle cells is related to expression of cyclin D, lipid Peroxidation injury to endothelial cell may induce proliferation of smooth muscle cells through enhancing expression of cyclin D.

Abstract:Aim To investigate the relationship between the enhanced proliferation and renin-angiotensin system (RAS) of aortic smooth muscle cells (SMC ) from spontaneously hypertensive rats .(SHR).Methods Proliferative activity of SMC was assessed by 3H-TdR incorporation and doubling time (DT).Angiotensin Ⅱ (Aug Ⅱ ) content and angiotensin converting enzyme (ACE) activity were measured by radioimmunoassay and colorimetry respectively.Results SHR SMC had stronger proliferative ability compared with Wistar-kyoto normotensive rats (WKY) while SHR SMC RAS was activated. Enhanced proliferation of SHR SMC was obviously inhibited with the long-term administration of captopril (Cap) and saralasin (Sar). The inhibition rate on HTdR incorporation of SHR SMC by 10-4 mol/L Cap was 31%±4% (p<0. 01 ) while the DT was prolonged for about 13 h (p<0. 01 ). Aug Ⅱ content and ACE activity were decreased for 25%±9%, 27%±13 % respectively. The inhibition rates on 3H-TdR incorporation of SHR SMC by 10-5 mol/L Sar was 20%±3% (p<0. 05) while the DT was prolonged for about 7 h (p<0. 05). The Aug I content that two types of rats synthesized and secreted increased while ACE activity of SHR SMC decreased by 10-s mol/L Sar.SHR, WKY SMC RAS were not influenced by shortterm administration of Cap.Conclusion Long-term administration of Cap and Sar suppressed SHR SMC growth through inhibition of Aug I generation or blockade of Aug I binding to its receptor.

Abstract:Aim in order to regulate the action of small molecular G protein (ras protein) for inhibition of smooth muscle cell (SMC) proliferation response to growth factor, basic fibroblast growth factor (bFGF).Methods Antisense oligomers, modified to prevent their own degradations, were used in a concentration of 6 pool/L introduced into the serum-free medium containing bFGF (100 mg/L) in which rat aortic SMC were cultured. By means of H-thymidine incorporation and immunocytochemistry methods, DNA synthesis and expression of proliferating cell nuclear antigen. (PCNA) in SMC were detected.Results These oligodeoxynucleotides (ODN), in a time-related manner, significantly lowered the DNA synthesis of SMC by more than 90% (compared with the control). When a same nucleotides sense ODN was used instead, showed only a little effect. lmmunocytochemistry indicated that the antisense ODN can markedly reduce expression of PCNA protein which is necessary for SMC proliferation. Conclusion Antisense G protein ODN strategies may be used to resolve clinical problems caused by growth factors initiated cell proliferation.

Abstract:Aim To study the relation between vascular angiotensin converting enzyme (ACE) activity and intimal hyperplasia in rabbit restenotic model and the effects of different doses of benazepril.Methods Angioplasty was performed in the left artery of 28 New Zealand white rabbits. Benazepril was administrated to treatment groups in lowdose(n=9,1mg/kg) and high-dose (n= 9, 10 mg/kg)respectively. All animals were sacrificed 2 weeks after angioplasty. The vascular morphometry included intimal and medial areas,thus ratio of intimal area to medial area. Serum and vascular ACE activities were determined by fluorimetric assay.Results The vascular ACE activity of angioplasty subgroup was 2. 7 times higher than that of the nonangioplasty subgroup (p<0.01). The high-dose benazepril significantly reduced the vascular ACE activity and intimal area, compared with angioplasty subgroup (p<0.01). But the low-dose benazepril only moderately inhibited the vascular ACE activity (24% down,p<0.05), and the intimal area did not alter significantly. The significant positive correlation was displayed between vascular ACE activity and intimal area (r=0.708, p<0.01).Conclusion The excessive expression of vascular ACE may play a pontential role in restenosis. The high-dose benazepril could inhibited intimal hyperplasia by suppressing vascular tissue ACE.

Abstract:Aim To examine the effect of sole or combining treatment of pravachol and inositoli nicotinatis on blood lipid in patients with hyperlipidemia.Methods 72 cases with hyperlipidemia were divided into pravachol group, inositoli nicotinatis group and combining treatment group. Treatment period lasted for 4 weeks,blood lipid parameters were measured before and after treatment.Results After treatment pravachol significant cend the levels of TC and LDLC, doesn't descend TG (TC: 7.0 ±1.4vs 5.9mmol/L, p<0. 05; TG: 2. 7±1.2vs 2.5±1.0 mmol/L, p<0.05; LDLC: 4.6 ±1.3vs 3.6±1.2mmol/L, p<0.05), inositoli nicotinatis significant reduce TG, doesn't descend TC,LDLC (TC: 7.0±1.4vs 6.4±1.5mmol/L, PRO.05; TG: 2.7±1.2vs 2.1±0.9mmol/L, p<0.05; LDLC: 4.6±1.2vs 4.3±1.3mmol/L, p<0.05).Decreased or increased magnitude of blood lipid composition in combining group were greater than those in pravachol group and inositoli nicotinatis group (TG:- 27.3%, -15. 6% and -7.5%, p<0. 05; TG:- 31.9%,-7.l% and -22.8%, p<0.05; HDL: +11.2%, +l.7% and +4.4%,p<0. 05). 39 cases that sole treatment was not effective received combining treatment for another 4 weeks, blood lipid composition have furture changed (TG:6.5±1.4 vs 4.5±1. 3mmol/L,p<0.01; TG: 2.6±1. 2 vs 1. 9±1. 1 mmol/L,p<0. 01; HDL: 1. 16±0. 22 vs 1.27f±21 mmol/L,p<0.05).Conclusion These data suggest that combining pravachol with inositoli nicotinatis treatment can enhance the reducing blood lipid effect, improving blood lipid composition.

Abstract:Aim Observe the effects of the centre-type and periphery-type obesity on serum lipids and lipoproteins level in the aged.The information about serum lipids,apolipoproteins from 84 cases of centre-type obesity,104 cases of periphery-type obesity and 101 case of normal weight of the aged was analyzed.Results Centre-type obesity has a serum lipid level disorder in accordance with what the periphery-type one has. Both obesities have an increase of total cholesterol (TC), triglyceride (TG) and apolipoprotein B and a decrease of high density lipoprotein cholesterol(HDLC) and apolipoprotein AI. The centre-type obesity. however, displays more remarkably than the Periphery-type one does. With increasing of the waist and hip ratio(WHR), the serum lipid level disorder become more serious. The incidences of the hyperlipidemia were 82. 2% and 47. 6% for the centre and periphery obesity respectively (p<0.01).Conclusion. The fat accumulation in abdomen of obesity aged may induce a more serious disorder of the serum lipid and apoproteins level. So, we should attach importance to observing and regulating the fat distribution in aged for the prevention and cure of the serum lipid and apoprotein level disorder.

Abstract:Aim The aim of this study was to evaluate the association of carotid arterial intima-media thickness(IMT) with coronary heart disease (CHD) and risk factors of cardiovascular disease.Methods IMT was measured by high resolusion Bmode ultrssound in 94 elderly subjects. The studied population were divided into three groups:① 32 subjects with normal cholesterol; ② 16 subjects with bordline hypercholesterolemia; ③ 46 subjects with hypercholesterolemia.Results The IMT was not significantly different among three groups with various cholesterol levels,whereas the IMT was positively correlated with age,blood pressure, serum total cholesterol and LDL cholesterol. The incidences of hypertension, smoking, cerebral infarction and CHD were obviously highten in the subjects with IMT>1. 0 mm compared with IMT<1.0 mm. Age was determined as an independent factor for intima-media thickening on multivariate Logistic regression. Conclusion Carotid artery IMT was affected, to various extent, by multi-factors in the elderly. Carotid arterial IMT, as a noninvasive index, could be used to observe the change of atherosclerosis in the elderly.

Abstract:Aim To study the effects of basic fibroblast growth factor (bFGF) on the repairment of the injured intima by balloon denudation in rat aorta. Methods The male Wistar rats were divided into six groups as follows, two early treatment groups (a 7day-group and a 21 day-group ), one late treatment group, and three control groups including a simulated operation group. The intima of the aortae was denuded by using a balloon catheter. bFGF was injected into the tail veins of the animals on the 1st, 2nd and 3rd day (early treatment) and on 15th, 16th and 17th day after balloon denudation (late treatment ), respectively. The denuded aorta rings were perfused in the Krebs-Henseleit's balance salt bath. The plasma NO levels were determined by the method described by Green and his colleagues, and the plasma endothelin levels and the cGMP content in the aortic tissue were measured by radioimmunoassay.ResultS Intravenous injection of bFGF, not only in the early treatment but also in the late treatment,could significantly promote the relaxation reaction induced by acetylcholine. The maximal relaxation mag nitude of the denuded aorta rings in the 7-day- treatment group and 21-day-treatment group were 2. 2 and 1. 7 times that of both control groups, respectively, and the maximal relaxation magnitude in the late treatment group was 2. 6 times as high as in control group.After denudation, the plasma NO2 levels of the 7-day and 21-day control group were lower by 12% and 27%, and the cGMP contents of both control groups were lower by 57% and 48%, whereas the plasma endothelin levels of both control groups were higher by 70% and 40%, respectively, than that of the simulated operation group. Meanwhile, the plasma NO2 levels of both early treatment groups were higher by 50% and 115%, and the cGMP content of both early treatment groups were higher by 106% and 100%, respectively, than that of the control groups, whereas the plasma endothelin levels were significantly lower.The results of the late treatment group were simular to that of the early treatment groups.Conclusion Using bFGF might promote the repairment of denuded endothelium, inhibit the overproliferation of denuded intima, and therefore might play a role in preventing restenosis of balloon denuded aorta.

Abstract:Aim The synthesis and release of endothelin (ET)in patients with coronary heart disease undergary percutaneous transluminal coronary angioplasty has not been concluded. This study examined the porsible association between endothelin and coronary atherosclerosis and evaluated the synthesis and release of endothelin in the presence of various stimuli that occur during percutaneous transluminal coronary angioplasty.Methods The plasma from femoral artery blood and urinary concentrations of endothelin immunoreactivity in 15 patients and 10 healthy control subjects were measured before and after percutaneous transluminal coronary angioplasty.Results The basic plasma and urinary ET-1 level was higher than the control subjects (<0.01).Changes were not detected in peripheral plasma concentrations of ET-1 within 24 h (p<0. 05), but found increase in urinang ET-l levels from 50±12 to 274±54pg/kg of creative a few hours after coronary angioplasty (p<0.01). The increase excretion persisted for more than 24 hours. It was found that systolic aortic pressure was correlated with basal uninary excretion of ET-l within the range of nomal (r=0 87, p<0.01, n=15), but balloon size, dilating times and duration were not associated with ET-l level.Conclusion ET-l concentration of patients with coronary heart disease was higher than the control subjects. Vascular injury during coronary angioplasty increase urinary ET-l levels a few hours after the procedure. This increase was not detectable by sampling of femoral artery blood. Systolic aortic pressure was related to urinary ET-l. Larger clinical studies are required to further elucidate the biologic importance of endothelin in patients with coronary heart disease.

Abstract:To investigate the relationship between serum lipoprotein (a) [LP (a)], plasma fibrinogen (Fg) levels and coronary stenosis documented by angiography in patients with coronary heart disease (CHD). One hundred and thirty-seven cases undergone coronary angiography whose serum LP (a) and plasma fibrinogen levels were determined. Results show that the serum Lp(a) mean levels were higher in 61 cases of CHD with multi-vessels disease (VD) than 31 control with none vessel disease. Plasma Fg levels raised significantly in CHD cases of single and multiple VD groups than None VD group. There was a mild relation between LP (a) and Fg level in multi-VD group (r = 0. 37, p<0. 05, n = 53). This study suggests that LP (a) and Fg blood levels all increase significantly in CHD cases, and there is certain relation between them.

Abstract:Aim Componing the acute efficacy and safety of percutaneous transluminal coronary angioplasty (PTCA) and percutaneous transluminal coronary rotational ablation (PTCRA) patients with coronary heart diseaseMethods Success rates, residual stenosis, and incidences of complications in both PTCA and PTCRAgroups were compared.Results The diameter stenosis was reduced from 80%±14% to 20%±10% using PTCA for 46 lesions in 40 patients, and reduced from 84%±9% to 29%±2% using PTCRA for 17 lesions in 10 patients. The residual stenosis significantly differed from each other (p<0.05). The success rates were 82.5% and 80%, respectively of PTCA and PTCRA (p>0.05). The overall incidences of complications were 17.5% and 80%, respectively for PTCA and PTCRA (p<0.001), with the incidences of major complications of respectively 2.5% and 5% (p<0.001). No death occurred in PTCA, while one patient died in PTCRA during the procedure.Conclusion Success rate, efficacy and safety in PTCA was superior to in PTCRA. Furthermore,PTCA has widespread indications. PTCRA is suitable merely to some "hard" lesions or some lesions anatomically unsuitable to PTCA. Adjunctive PTCA is necessary to improve PTCRA efficacy when residual stenosis is remarkable.