自由基对爪蟾卵母细胞表达的大白鼠脑皮层谷氨酸受体和5－羟色胺受体的作用

Effect of active oxygen free radical on glutamic acid receptorand serotonin receptor of rat cerebral cortex expressedby Xenopus oocyte

采用爪蟾卵母细胞和黄嘌呤氧化酶一次黄嘌呤反应系统研究了自由基对大白鼠脑皮层谷氨酸受体和５－羟色胺受体的作用。自由基抑制谷氨酸和５－羟色胺引起的去极化反应，但不影响膜的被动电学参数。自由基对受体的作用表现为去极化幅度下降及半衰退时间缩短；去极化的潜伏期和上升时间延长（Ｐ＜０．００１或Ｐ＜００１），说明白由基作用于移植到卵母细胞膜上的受体，抑制了谷氨酸和５－羟色胺引起的去极化反应。提示在本实验条件下，神经递质受体自由基作用的敏感性高于卵母细胞的质膜。此标本适于研究自由基对神经递质受体的作用。

To study the effect of active oxygen free radi-cal on glutamic acid (Glu) and serotonin (5-HT) receptors ofrat cerebral cortex. an oocyte translation system for receptorexpression, and xanthine oxidase-hypoxanthine reactionsystem were used. The results showed that the depolanzationresponses induced by Glu and 5-HT were inhibited by activeoxygen free radical, and were manifested by reduction ofdepolarization amplitude and t1/2 of decay. and by signifi-cant prolongation of its rising time and latent period(P< 0.001 or P < 0.0 1 ). On the other hand. the passive electri-cal membrane parameters were not affected by superoxideanion. Therefore. the Glu and 5-HT receptors were moresensitive to active oxygen free radical injury than oocyteplasma membrane. It was suggested that the effect ofsuperoxide anion on the transplanted receptors was responsi-ble for inhibition of depolarization induced by Glu and5-HT. Consequently, this preparation is suitable to study theeffect of active oxygen free radical on neurotransmitterreceptors.