急性缺氧对青年、老龄大鼠血浆和脑组织中内皮素、一氧化氮含量的影响

Effects of acute hypoxia on plasma and cerebral cortex contents of endothelin and nitric oxide in young and old rats

目的 对比分析急性低压缺氧对青年、老龄大鼠血浆和大脑皮质中内皮素 (ET)、一氧化氮 (NO)含量和大脑皮质光、电镜形态学的影响。 方法 将 2 6只 2月龄和 2 6只 2 2月龄雄性 Wis-tar大鼠各随机分成对照组和缺氧组。急性低压缺氧 (80 0 0 m,30 min)后测定各组血浆和大脑皮质匀浆中 ET、NO的含量 ,观察大脑皮质光、电镜形态学的变化。 结果 急性重度低压缺氧后青年、老龄大鼠血浆和大脑皮质中 ET、NO含量明显升高 (P<0 .0 1或 P<0 .0 5 ) ,大脑皮质发生水肿、变性等损害。老龄大鼠缺氧后 ET、NO升高的幅度比青年大鼠更明显 ,其缺氧性脑水肿损害也比青年大鼠重。 结论 老龄大鼠比青年大鼠对急性缺氧更为敏感。ET、NO可能参与了缺氧性脑损害的病理过程。

Objective To contrast the effects of acute hypobaric hypoxia on the plasma and cerebral cortex contents of endothelin(ET) and nitric oxide(NO) and the pathologic changes of cerebral cortex in young rats with those in old rats. Methods Fifty two 2 month old and 22 month old Wistar rats were divided into control group and hypoxia group.The ET and NO contents of plasma and cerebral cortex were measured and the pathologic changes of cerebral cortex were examined after acute hypobaric exposure (8 000 m,30 min). Results The ET and NO contents of plasma and cerebral cortex in hypoxia group were significantly increased as compared with those of control group in both young and old rats( P <0.01 or P <0.05). The concentrations of ET and NO in old rats increased more prominently than those in young rats after hypoxia exposure.The microscopic and electronmicroscopic examinations showed that the vascular endothelium and neurones of cerebral cortex were injured in rats of hypoxia group,and the pathological changes in old rats were more prominent than those in young ones. Conclusions The 22 month old rats were more sensitive to hypoxia than 2 month old rats.ET and NO may participate in the pathogenesis of hypoxic brain injury in rats.