大鼠急性脑缺血时多巴胺β－羟化酶和单胺氧化酶的活性变化

A Study of Dopamine β hydroxylase and Monoamine Oxidase Activity After Rat Cerebral Ischemia

对大鼠急性脑缺血５ｈ后脑组织中多巴胺β－羟化酶（ＤＢＨ）和单胺氧化酶（ＭＡＯ）活性以及血清中ＤＢＨ活性进行了测定。结果显示，实验组动物缺血脑组织之ＤＢＨ活性明显低于对照组（Ｐ＜０．００１），而ＭＡＯ活性无明显改变（Ｐ＞０．０５）。说明脑缺血时ＤＢＨ活性下降和ＭＡＯ仍能活跃地降解去甲肾上腺素（ＭＥ），是缺血早期脑内ＮＥ下降的一个重要原因。实验组血清ＤＢＨ活性略高于对照组，但无显著性。

Dopamine β hydroxylase(DBH)and monoamine oxidase(MAO)activity in rats brain tissues and DBH in sera were investigated after 5 hours of cerebral ischemia.The results showed that DBH activity in ischemic cerebral tissue was significantly lower than that of control( P <0 001),while the MAO activity was still normal ( P >0 05).They suggested that reduced DBH activity and that NE was still being actively deaminated by MAO which was one of the important reasons of low NE concentration in ischeamic brain.Sera DBH activity had a lightly higher level than that of control,but is not significant( P >0 05),it was not enough to prove that the sympathetic nerve function had increased after cerebral ischeamia.