纤溶系统激活的实验研究—儿茶酚胺对纤溶活性的影响

Experimental study of fibrinolytic activation-effect of catecholamines on fibrinolytic activity

用不同浓度儿茶酚胺灌流大鼠下肢血管床,观察它们对血管内皮细胞释放纤溶酶原激活剂(PA)的作用。结果显示,同样浓度(25μM)儿茶酚胺所引起的PA释放效应以肾上腺素为最强,去甲肾上腺素次之,异丙基肾上腺素作用最弱,PA活性分别是0.202±0.038,0.117±0.006,0.097±0.007(U/ml,(?)±SE)。β肾上腺素能受体阻断剂心得安完全拮抗异丙基肾上腺素诱导PAL活性升高,部分抑制去甲肾上腺素、肾上腺素的作用。α、β肾上腺素能受体阻断剂(酚妥拉明+心得安)协同作用时,肾上腺素、去甲肾上腺素的这种PA活性升高效应基本抑制。本文还发现,剧烈运动产生应激反应时血浆去甲肾上腺素含量明显升高,为2.45±0.45(ng/ml,(?)±SE),与对照值(0.88±0.20)比P<0.01。与此同时伴随纤溶活性显著增加。实验结果提示:外源性儿茶酚胺诱导PA释放效应主要经由β肾上腺素能受体介导,α肾上腺素能受体涉及部分作用,内源性儿茶酚胺水平升高可引起纤溶活性增加。

The present study, using the different catecholamines, observed the effects on plasminogen activator (PA) activity release in the vascular wall of rat hindlegs. The results showed that adrenaline perfusion induced the highest PA activity in three different catecholamines. Propranolol completely blocked PA activity induced by isoprenaline. PA activity induced by adrenaline or noradrenaline was completely inhibited by propranolol combined with phentolamine. During physiological stress the increase of plasma noradrenaline level was accompanied with higher PA activity. These data indicated that exogenous catecholamines produced a increase of PA activity via β-adrenoreceptors stimulation mainly, as well as α-receptors partially. The endogenous increase of catecholamines showed the same effect on fibrinolytie system.