开搏通、氯沙坦对大鼠腹主动脉缩窄后纤溶活性变化的影响

目的：探讨压力对纤溶活性的影响及纤溶活性与肾素血管紧张素系统的可能关系，探寻ACEI及AT1拮抗剂减少心肌梗塞再发生的机理。方法：用发热底物法测定大鼠腹主动脉缩窄后血浆纤溶酶原激活抑制物-1(PAI-1)和组织型纤溶酶原激活物（t-PA）的活性变化以及肼苯达嗪、开搏通、氯沙坦应用后其活性变化。结果：发现腹主动脉缩窄后，随颈动脉压力升高，PAI-1活性升高，t-PA活性降低，纤溶活性降低；应用肼苯达嗪、开搏通、氯沙坦在有效降低压力同时，PAI-1活性降低，t-PA活性提高，纤溶活性提高，且开搏通及氯沙坦改善纤溶活性的作用更明显，此作用二者之间无显著差别；由此推论压力与纤溶活性密切相关，有效降低压力，提高纤溶活性。结论：肾素血管紧张素系统与纤溶系统有潜在的内在联系，ACEI及ATI拮抗剂均能提高纤溶活性。

EFFECTS OF CAPTORIL AND LORSARTAN ON FIBRINOLYTIC ACTIVITY IN ABDOMINAL AORTA CONSTRICTION RATS

Objective: To study the mechanism of angiotensin - converting enzyme inhibitor (ACEI) or antagonist ol angiotensin II receptors - 1 (AT1) in reducing the risk of recurrent myocardial infarction. Method: The model of abdominal aorta constriction had been established in rats. The animals were divided randomly into sham - operative group, operative group, hydralazine hydrochloride group, captopril group, and lorsartan group. Captopril, lorsartan and hydralazine were separately given until the post - operation seventh day. Blood pressure and activities of PAI -1 and t- PA of these rats were measured. Result: In operative group, blood pressure and activity of PAI - 1 increased (115 + 14 mmHg vs 262 + 13 mmHg; 8.6 + 14 Au/ml vs 13.08 + 1.6 Au/ml, p < 0.01), but activity of t - PA decreased from 3.54 + 1.1 Au/ml to 1.77 + 1.8 Au/ml (p<0.0l). In hydralazine, captopril and lorsartan groups, blood pressure and activity of PAI - 1 decreased (10.02 + 1.9 Au/ml, 8.23 + 1.3 Au/ml and 8.27 + 1.5 Au/ml vs 13.08 + 1.6 Au/ml, respectively, p < 0.01) . It was found that when blood pressure decreased, the fibrinolytic activity increased. The improvement of fibrinolytic activity in captopril and lorsartan groups was more significant than that in hydralazine group (p<0.05). Conclusion: Fibrinolytic activity was correlative with blood pressure and rennin - angiotensin system, and both angiotensin - converting enzyme inhibitor and antagonist of angiotensin II receptors could elevate the fibrinolytic activity.