血管紧张素Ⅱ对大鼠主动脉PAI-1,tPA活性的影响及不同肾素活性状态下纤溶功能的变化

Effects of angiotensin Ⅱ on PAI-1 and tPA releases in isolated aorta and changes of fibrinolytic function in different states of RAS in rats

目的 :观察血管紧张素 (Ang )对大鼠主动脉纤溶酶原激活物抑制剂 (PAI- 1)、组织型纤溶酶原激活物(t PA)活性的影响及不同肾素活性状态下纤溶功能的变化。方法 :1采用离体大鼠主动脉条孵育的方法 ,在孵育液中分别加入不同浓度 (10 - 9,10 - 8,10 - 7,10 - 6m ol/ L) Ang ,用发色底物法分别测定孵育液中 PAI- I及 t PA活性。2 2 4只雄性 8周龄正常血压 WKY大鼠随机分为高盐组和对照组 (n=12 ) ,分别给予 2 0 g/ L 盐水和清水喂养 6周 ,制备不同肾素活性模型动物 ,放射免疫法测定血浆肾素活性 (PRA)和血浆 Ang ,同时用发色底物法分别测定血浆中 PAI- 1及 t PA活性 ,用 Pearson方法做多元相关分析。结果 :不同浓度的 Ang 可使大鼠主动脉 PAI- 1活性增加 ,t PA活性无变化。低盐组 PRA和血浆 Ang 水平升高 ,同时 PAI- 1活性增加 ,而 t PA活性无变化 ,多元相关分析显示 ,血浆 PAI- 1活性与血浆 Ang 水平的对数呈正相关。结论 :肾素

AIM:To observe the effects of angiotensin Ⅱ(AngⅡ) on PAI-1 (plasminogen activator inhibitor-1) and tPA (tissue type plasmingen activator) releases in isolated aorta and changes of fibrinolytic function in different states of RAS (renin-angiotensin system) in rats.METHODS:①Tissue slices of rat aorta were incubated with increasing concentrations of AngⅡ (10a?a(c)-9aa,10a?a(c)-8aa,10a?a(c)-7aa,10a?a(c)-6 mol/L) and the activity changes of PAI-1 and tPA in siolated vessle incubation were measured by spectrphotometric assay;②Twenty-four 8-week-old male WKY rats were divided into two groups,drinking 20 g/L NACL and distilled water respectively for 6 weeks to induce different states of RAS. PRA (plasma renin activity) and AngⅡ levels were measued by radioimmunoassays. PAI-1 and tPA activities in plasma were measured simultaneously. Bivariable correlations of PAI-1 and PRA,AngⅡ were analysed by Pearson coefficients. RESULTS:The activities of PAI-1 in incubation concentration-dependently increased but tPA was not affected by AngⅡ,In the activity of PAI-1 in plasma increased with the increase of PRA and AngⅡ in rats drinking distilled water. PAI-1 was positively correlated with AngⅡ of logarithm. CONCLUSION:RAS involves in the regulation of fibrinolytic function.