Abstract:We investigated the effects of probucol on endothelial damage induced by exogenous free radicals and on activity of nitric oxide (NO).The results demonstrated that rabbit aortic rings incubated with xanthine(X,100 μmolL-1) and xanthine oxidase(XO,100 U·L-1) for 30min showed weak response to acetylcholine and that cultured bovine aortic endothelial cells incubated with X-XO for 30 min showed decrease of NO release and increase of malondialdehyde content.Probucol (40, 80 and 120 μmol·L-1) could protect endothelial cells from injury due to X-XO in a concentration-dependent menner, Inactivator of NO oxidized hemoglobin(OHb, 100μmol·L-1), not synthesis inhibitor of NO NG-nitro-L-arginie(NG-L-Arg,100 μmol·L-1), could abolish the effect of probucol. In the inhibitive experiment of NO synthesis and effect, we observed that the acetylcholine -induced relaxation ratio of aortic rings was reduced by NG-L-Arg, OHb and NO antagonist methylene blue(MB,100 μmol·L-1).Probucol 80 μmol·L-1 could contend with the relaxing inhibition of O Hb and MB not NG-L-Arg. Our data indicate that probucol can protect endothelial cells from damage due to free radicals. The mechanism of such protection may be partly associated with the maintenance of NO activity.

Abstract:A large number of growth factors and cytokines involved in the processes of atherogenesis.A variety of in vitro and in vivo studies gave indicated that tumor necrosis factor (TNF)and nitric oxide (NO)have close relation to atherogenesis. In order to find out the secretion of TNF and NO production by lipopolysaccharide-stimulated macrophages preincubated with minimally modified low density lipoprotein(MM LDL)and oxidized low density lipoprotein(OLDL). The results were that after 48 hours treated, the secretion of TNF induced by MM LDL increased up to 2-fold, and the increase of NO production could be up to 5-fold. However, OLDL sharply inhibited the production of TNF in a concentration-and time-dependant with maximum inhibition(>90%)after 48 h preincubation with OLDL,and NO production did not increase(p>0.05). Concerning with other studies, we suggested that in the different stages of atherogenesis, tbe amount of production of TNF and NO by vessal cells might be different, but more evidents in vivo are needed to find out this mechanism.

Abstract:The chemotactic activity of lowdensity lipoprotein(LDL), oxidized LDL(OLDL),very LDL(VLDL) and oxidized VLDL(OVLDL)for human monocytes was examined, respectively,by micropore filter mothod using modified Boyden chamber. The results showed that LDL was chemotactic for monocytes, and its chemotactic activity increased significantly when it was modified by oxidation. However VLDL was not chemotactic,whereas OVLDL was significantly chemotactic for human blood monocytes.

Abstract:In the present study, Nilsson's venous outflow method was used to investigate the changes of cerebral blood flow(CBF)in aged and adult SD rats during cigarette smoking. In the aged rats,the CBF increased 25.7% and 36.1% of the control respectively after 1 min and 5 min smoking.While in the adult rats, the respective values are 22.7%and 107.8%. Blood pressure(BP),pHa and PaO2 were also observed to decrease after smoking, but PaCO2 is increased. Cerebrovascular responses to smoking were obviously smaller in the aged than in the adult rats, seemingly due to a weaker function of cerebrovascular regulation in the aged rats, owing to perhaps a decrease of β- receptor and a changes of cerebrovascular morphology.

Abstract:Present experiment explored internal relationship between oxidized low density lipoprotein(OLDL) and endothelin (ET) on promoting cellular proliferation using cultured rabbit's vascular smooth muscle cells(VSMC).It was found that both could stimulate VSMC to proliferate;BQ123, antagonist of ETA receptor, could significantly inhibit the role that OLDL promoted VSMC to proliferate; 3H-TdR incorporation decreased by 13.3% compared with only OLDL group. Radial immunologic measurement on medium of cultured cells indicated that BQ123 could descended release of ET by 28.9% compared with only OLDL group.The results of immunocytochemistry were all compatible with above. It was suggested that the role that OLDL promoted VSMC to proliferate may be realized by ET in part in atherosclerotic pathogenesis.

Abstract:This study was to investigated the effect of exogenous oxygen free radicals(OFR)on the rabbit basilar artery. Exogenous OFR were generated by electrolysis of Krebs' solution. The perfusion pressure and malonyldialdehyde content in basilar artery were increased, meanwhile release of endothelium derived relaxing factor,nitrite content and superoxide dismutase activity decreased after OFR damage, These data indicated that OFR induced cerebral vasospasm is mainly mediated by cerebral vascular endothelial damage and lipid peroxide formation.

Abstract:The ultrastructural changes of aorta in adult Wistar rats with streptozotocin(SZ) induced non-insulin-dependent diabetes mellitus were observed.Meanwhile, plasma lipid,lipid peroxides(LPO) and supperoxide dismutase(SOD) levels were measured.The results showed that both diabetic group and fat group had ultrastructural pathologic changes in their wall and the situation in diabetic group is severe than in fat group and the differences in subendothelial depth,numbers of layers of smooth muscle cells in intima and points scored for damage in intima were very significant(p< 0. 01). The plasma triglycerides, total cholesterol and low density lipoprotein cholesterol levels were increased(p< 0. 01), but high density lipoprotein cholesterol/low density lipoprotein cholesterol was decreased(p<0. 01)in fat group and diabetic group. The plasma LPO levels in diabetic group and fat group were increased(p<0. 01), the plasma SOD levels in diabetic group was decreased but increased in fat group(at the forth week, p<0.05; at the tenth week,p<0. 01). The results above indicate that the experimental SZ-induced non-insulin-dependent diabetes mellitus rats rats have the early ultrastructural pathologic changes in aorta wall,which would be associated with the increase of LPO, decrease of SOD and the disorders of lipid metabolism.

Abstract:Using histopathological method the authors compared the atherosclerotic lesion of the aorta in 241 cases of young adults collected from both high morbidity area of Beijing(104 cases) and low prevalence district of Nanning(137 cases).Causes of death were violence and traffic accident. Victims ages were 15~39 years.Intimas of aortae were divided into normal and type Ⅰ~Ⅴ ofatherosclerotic lesion. The result showed that the total prevalence of all types of atherosclerosis of aorta was significantly higher in Beijing group (62.5%) than in Nanning(53.1%). The detection rate of early lesion(typeⅠ+Ⅱ) was similar in the 2 groups. However, prevalence of intermediate(type Ⅲ) and advanced lesion(type Ⅳ+Ⅴ)in Beijing group was considerably higher than those Nanning (14.4% vs 8.7% and 6.9% vs 3.4%, p<0. 05 respectively). Lymphocytic intiltration in intima was more freguently encounted in type Ⅱand type Ⅲ in Beijing group than in Nanning (27.6% vs 8.9% and 93.5% vs 75.0%,p<0. 01 respectively).No significant difference in lymphocytic infiltration between the 2 groups was found in lesion of type Ⅰ, Ⅳ and Ⅴ. This data indicates that the difference of the atherosclerotic lesion existed in both high morbidity area of Beijing and low prevalence district of Nanning is mainly the different prevalence of intermediate(type Ⅲ) and advanced lesion(type Ⅳ+Ⅴ), and close relationship might exist between lymphocytes and atherosclerosis as well.

Abstract:Resistance to insulin-stimulated glucose uptake is present in the majority of patients with impaired glucose tolerance or non-insulin dependents diabetes millitus (NIDDM)and in obese. Coronary heart disease(CHD) is prevalent in both obesies and diabetic condition with insulin resistance.To test whether CHD is associated with insulin resistance independently of obesisty and diabetes,we measured serum insulin levels during oralglucose tolerance test(OGTT) in 32 patients with CHD,who have normal body weight, normal blood pressure, and normal OGTT,and 23 normal subjects. Plasma triglyceride(TG)and total cholesterol(TC) were determined in fasting condition and after glucose load.We found that the insulin levels of CHD is much higher than those of controls after glucose load, meanwheal TG and TC levels are higher than those of controls. The results showed that CHD exists insulin resistance state or hyperinsulinemia; It may involve in the etiology and clinicalcourse of CHD as a risk factor.

Abstract:Effects of Oenothera biennis L complex prescription on plasma lipids and experimental athrosclerosis of rabbits were observed.In the proventive group with supplement of Oenothera biennis L complex prescription(1 g. k-1 per day)for 16 weeks, the levels of serum total chotesterol and low density lipoprotein significantly reduced(P <0. 01 and p< 0. 05, respectively),the level of serum high density lipoprotein cholesterol increased (p<0. 01), the proliferation of smooth muscle cells and the development of aortic atherosclerotic plague were inhibited.