局灶脑缺血后早、晚期一氧化氮合成酶的活性变化

Changes of NOS Activity After Focal Cerebral Ischemia

一氧化氮(NO)在脑缺血中起重要作用,一氧化氮合成酶(NOS)作为NO合成的关键酶,其活性变化直接调节NO的生成量及生物学效应。本文在建立兔MCAO局灶脑缺血模型基础上,测定缺血后不同时间缺血区和正常脑组织的NOS活性。结果显示,脑缺血早期(1h内)NOS活性突然升高,随之下降;脑缺血后24h NOS活性又升高,至48h、96h明显升高。

Nitric oxide (NO) is involved in cerebral ischemia and affects ischemic insult. NOS acts as the key-enzyme of NO synthesis, the changes of its activity directly regulate the quantity of NO production and its biological effect. In this study, on the basis of rabbit model of middle cerebral artery occlusion, the activities of NOS in the ischemic site and normal brain tissue at the different ischemic time were determined. The results showed that its activity was increased and then decreased during 1 h after cerebral ischemia; at 24 h after cerebral ischemia its activity was reincreased and was significantly increased at 48 h, 96 h after cerebral ischemia.