过刊浏览

新霉素抑制PC12细胞烟碱受体介导的反应

石丽君, 王春安

解放军北京军医学院生理学教研室.北京 100071；第二军医大学生理学教研室.上海 200433

摘要

采用全细胞膜片钳技术,以大鼠肾上腺嗜铬细胞瘤细胞(PC12)为标本,观察了新霉素对乙酰胆碱诱发电流(I_(ACh))的影响。药理学鉴定表明,PC12细胞上的I_(ACh)是通过ACh激动烟碱受体引起的。钳制电压为-80mV时,ACh(30#mu#mol/L)诱发一内向电流;细胞外同时给予新霉素(0.01-1mmol/L)和ACh(30#mu#mol/L),可显著抑制I_(ACh)峰值。此抑制作用迅速、可逆,呈浓度依赖性。用新霉素预处理细胞3-8min不影响其对I_(ACh)的抑制作用。用外源性蛋白激酶C(PKC)激动剂激活PKC,同样可抑制I_(ACh),而细胞内透析PKC抑制剂(PKCI 19-31,0.1-5#mu#mol/L)不影响新霉素对I_(ACh)的抑制作用。以上结果提示,新霉素对PC12细胞的I_(ACh)有抑制作用,这是一种与磷脂酶C阻断无关的药理学效应。

关键词： 氨基甙类抗生素; 烟碱受体; 大鼠肾上腺嗜铬细胞瘤细胞; 膜片钳技术

Neomycin inhibits nicotinic receptor-mediated response in pheochromocytoma (PC12) cells

Shi Lijun, Wang Chunan

Department of Physiology,Beijing Medical College of PLA.Beijing 100071

Abstract

Neomycin is one of the aminoglycoside antibiotics, and on the cellular level it inhibits phospholipase C. The effects of neomycin on the acetylcholine (ACh)-induced current (I_(ACh)) were studied in pheochromocytoma (PC12) cells by using the whole-cell clamp technique. The I_(ACh) on PC12 cells proved to be generated through activation of the neuronal nicotinic receptor. ACh (30 #mu#mol/L) induced an inward current at a holding potential of -80mV. When the cells were applied with neomycin on the peak of I_(ACh) was observed. This effect was fast, reversible and concentration-dependent. Pretreatment with neomycin for 3-8 min had no influence on its inhibitory effect. Activation of protein kinase C by using an exogenous activator exerted an inhibitory action on I_(ACh). However, intracellular dialysis with a PKC inhibitor (PKCI 19-31, 0.1-5#mu#mol/L) did not affect the inhibitory effect of neomycin. The results obtained suggest that neomycin exerts an inhibitory effect on I_(ACh) without involvement of the blockage of phospholipase C.

Key words: Aminoglycosides;Nicotinic acetylcholine receptor;Pheochromocytoma cells;Patch clamp techniques

收稿日期：　　录用日期：

通讯作者：　　E-mail:

引用本文：

石丽君, 王春安. 新霉素抑制PC12细胞烟碱受体介导的反应[J]. 生理学报 2002; 54 (5): .

Shi Lijun, Wang Chunan. Neomycin inhibits nicotinic receptor-mediated response in pheochromocytoma (PC12) cells. Acta Physiol Sin 2002; 54 (5): (in Chinese with English abstract).