缺氧敏感性不同的大鼠血小板活性的比较研究

A comparative study of platelet activity in two strains of rats with different susceptibility to hypoxia

HT(Hilltop SD)缺氧敏感大鼠与普通W(Wistar)大鼠,分平原对照组与置模拟5000米高度低压舱10天的慢性缺氧组。慢性缺氧组与对照组肺动脉收缩压的均值(PAP),在HT大鼠分别为51.9±14.2与31.3±3.0mmHg,P<0.001,慢性缺氧组比对照组高65.8%;W大鼠分别为39.7±7.4与28.9±4.7mmHg,P<0.001,慢性缺氧组比对照组高37.4%。对照HT大鼠全血及肺组织5-羟色胺(5-HT)高于对照W大鼠(P<0.05)。慢性缺氧组HT大鼠血小板数增加,与对照组相比,P<0.01;全血及肺5-HT明显减少,与对照组相比,P<0.001及P<0.05;血浆TXB_2增高,与对照组相比,P<0.001;对ADP诱导血小板聚集敏感性降低。慢性缺氧组W大鼠以上指标变化与HT大鼠相似,除血小板聚集外,HT大鼠以上变化比W大鼠更明显。提示对照组两种大鼠血小板功能状态不完全相同,慢性缺氧时,HT大鼠血小板活化程度高于W大鼠,这在HT大鼠肺动脉对缺氧的增压反应敏感中可能起一定作用。

HT(Hilltop SD) rats with high susceptibility to hypoxic pulmonary hypertension and W(Wistar) rats were divided into control group(sea level)and chronic hypoxic group. The rats of chronic hypoxie group were kept in a hypobaric chamber at a simulated altitude to 5000 m for 10 days. After exposure to chronic hypoxia for 10 days the elevation of pulmonary arterial presure, the increase of platelet count and plasma TXB_2, the decrease of whole blood and pulmonary tissue 5-HT in HT rats were much more obvious than those in W rats. But the decrease of platelet aggregation induced by ADPin W rats was much more obvious than that in HT rats. These reaults showed that exporure to high altitude for 10 days led to the platelet activation. The extent of platelet activation in HT rats was more obvious than that in W rats. This may be one of the reasons showing that pressor effect of pulmonary artery in HT rats has higher susceptibilipy to hypoxia, and also one of the mechanisms of adaptable response to chronic hypoxia.