卵胞内微注射mRNA后胞膜上出现的新离子流

以胞内微注射技术向爪蟾卵内注射羊气管上皮细胞抽提的Poly(A)~ mRNA,以电压钳技术观察卵膜离子流的变化。注射前卵膜上主要有Ca~(2 ),Cl~-,K~ 和Na~ 流,在高钙溶液(10Ca-ND96)中,瞬间的Ca~(2 )激活Cl~-流较大,此离子流可被9-羟蒽阻断。注射mRNA后在9-羟蒽存在的情况下,向浴槽加入1mmol/L 8-Br-cAMP后新出现一个电压敏感的离子流,使电流电压曲线的零电流电位向右移;但在注射去离子水组未见此离子流。表明羊气管上皮里含有cAMP敏感的离子通道,并可被移植到爪蟾卵膜上。

AN ION CURRENT EXPRESSION AFTER INTRACELLULAR MICROINJECTION OF mRNA IN THE XENOPUS OOCYTES

Xenopus oocytes were injected with Poly(A) mRNA obtained from the sheep trachea epithelial cells. Macroscopic currents through voltage operated channels were recorded using voltage clamping technique when the endogenous calcium-dependent chloride current was blocked by 2 mmol / L anthracene-9-carboxylate. A 8-Br-cAMP sensitive membrane conductance was observed in the oocytes injected with mRNA but not in that injected with H2O. These results indicate that there is a cAMP sensitive ionic channel in the poly(A) mRNA from the sheep trachea epithelial cells, which could be transplanted into the membrane of the Xenopus oocyte.