高压培养对血管内皮细胞t-PA和PAI-1的影响及卡托普利干预的效果

Effects of high hydrostatic pressure on the t-PA and PAI-1 secretions of vascular endothelial cells and the interfering results of Captopril

目的:高血压常伴有纤溶功能的异常,但其机制尚不清楚。本研究拟观察高静水压培养对人脐静脉内皮细胞(HUVECs)t-PA和PAI-1的影响以及卡托普利的干预效果,并探讨其可能的作用机制。方法:选用第4～6代HU-VECs,接种于24孔培养板中。依培养压力分为3组:大气压组(0mmHg),中压组(90mmHg),高压组(180mmHg)。在同一压力组,根据不同药物干预又分为两个亚组。即对照组(Ctrl)和卡托普利组(Cap,10-5mol/L)。每组6份标本。采用ELISA法测定上清液t-PA和PAI-1的抗原浓度,并用细胞内总蛋白进行标化(单位:ng/μg proteins)。同时测定细胞内Ca2+浓度(nmol/L)。结果:与大气压组相比,中压和高压组t-PA浓度均显著降低,PAI-1浓度显著增高,t-PA/PAI-1比值显著降低,[Ca2+]i也显著增高。卡托普利对大气压组的t-PA、PAI-1和[Ca2+]i无显著影响,但在两个高压组,卡托普利显著升高t-PA浓度,显著降低PAI-1浓度,t-PA/PAI-1比值显著升高,[Ca2+]i显著地降低。结论:高静水压可损害内皮细胞的纤溶功能,而卡托普利的干预可降低高压所升高的[Ca2+]i,并改善高静水压对内皮细胞纤溶功能的影响。

Objective： Clinical studies have demonstrated that hypertension often accompanies abnormality of fibrinolytic function. In this study,we investigated the effects of high hydrostatic pressure on the concentrations of t-PA and PAI-1 antigen in culture medium of human umbilical vein endothelial cells（HUVECs） and observed the interfering results of Captopril. Methods： HUVECs harvested between passages 4 and 6 were used for the experiments.According to the cultured pressure, they were divided into three groups：atmospheric pressure group（0 mmHg）,middle pressure group（90 mmHg）, and high pressure group（180 mmHg）. The above three groups were respectively divided into two subgroups（6 samples/subgroups）, control group and Captopril group（10^-5 mol/L）. At the end of the culture period, supernatants were collected to measure the concentrations of t-PA and PAI-1 antigens by using ELISA kit. Concentrations of t-PA and PAI-1 antigens were normalized with intracellular proteins（Unit： ng/μg proteins）. Meanwhile, the concentration of intracellular free calcium （[Ca^2＋]i） was detected（Unit：nmol/L）. Results： Comparing with atmospheric pressure group, high hydrostatic pressure induced a dramatic reduction in t-PA antigen and a dramatic increase in PAI-1 antigen. Meanwhile, high hydrostatic pressure significantly increased [Ca^2＋]i. At atmospheric pressure group, captopril showed no significant effects on the concentrations of intracellular calcium, t-PA and PAl-1 antigens. However, capropril significantly reversed the effects of high hydrostatic pressure, increased the level of t-PA, decreased the level of PAl-l, decreased [Ca^2＋]i. Conclusion： High hydrostatic pressure can decrease the level of t-PA antigen and increase the level of PAI-1 antigen in HUVECs culture medium, which results in abnormality of fibrinolytic function. Captopril can depress [Ca^2＋]i increase induced by high hydrostatic pressure, and improve its fibrinolytic function.