爪蟾卵母细胞表达的淋巴细胞mAch受体的氧应激损伤

The action of free radical on muscarinic receptors of lymphocytes

目的和方法：将羊外周血淋巴细胞ｍＲＮＡ注入非州爪蟾卵母细胞胞浆内，借助卵母细胞的翻译系统，表达淋巴细胞的Ｍ型Ａｃｈ受体（ｍＡｃｈＲ）并移植到卵母细胞膜上。电位箝位法检测受体电流，观察氧应激对电流的影响。电生理实验前，将注射ｍＲＮＡ后的卵母细胞暴露于次黄嘌呤－黄嘌呤氧化酶或ＦｅＳＯ４－Ｈ２Ｏ２自由基反应系统，用电压箝位记录系统观察自由基对表达受体电流的作用。结果：随着自由基浓度增加，作用时间延长，表达的ｍＡｃｈＲ电流幅度下降；超氧化物歧化酶（ＳＯＤ）或过氧化氢酶（ＣＡＴ）可分别对抗Ｏ－·２和·ＯＨ造成的电流下降。结论：自由基对表达的ｍＡｃｈＲ电流的损伤作用存在量效和时效关系，ＳＯＤ和ＣＡＴ能分别有效地消除Ｏ－·２、·ＯＨ。

Abstract AIM: To determine the action of free radical on muscarinic receptor of lymphocytes of sheep peripheral blood.METHODS: Muscarinic receptors were transplanted into the membrane of Xenopus laevis oocytes by the translation system of oocytes injected with lymphocytes mRNA. The oocytes were exposeed to xanthine oxidase-hypoxauthine reaction system and FeSO 4-H 2O -· 2 reaction system to generate O [SX(B-*3]-· 2 and ·OH free radical. The ion current of the receptors were tested by means of voltage-clamping method. RESULTS: The current response induced by Ach was inhibited by free radical, which was manifested by reduction of current amplitude. The inhibition was dosage-dependent and time-dependent. CONCLUSION: Superoxide dismutase and catalase were able to eliminate the action of free radical and to protect the muscarinic receptors from free radical damage. MeSH Lymphocytes; RNA; Xenopus; Free radicals; Muscarine; Receptors, cholinergic