鼠脑神经递质受体在卵母细胞上的表达

Expression of Neurotransmitter Receptors from Mouse Brain in Xenopus Oocytes

把提取的鼠脑 m RNA注射到卵母细胞内 ,在卵母细胞上以双电极电压钳技术研究某些递质的诱导电流。实验发现除卵母细胞本身所具有的 muscarine受体外 ,还有多种受体明显地在卵母细胞上表达。卵母细胞膜上的表达受体的反应可分平滑型、振荡型、复合型三类。其反应类型与所开启的通道及通透离子有关。平滑型反应的受体与离子通道为一复合体 ,激动剂开启其自身离子通道。而振荡型反应是递质通过第二信使的介导 ,引起胞内 Ca2 +库中的 Ca2 +释放 ,开启卵母细胞膜本身的 Cl-通道 ,产生 Ca2 +依赖的 Cl-电流 ,构成振荡型电流反应的主要成分。

Two electrodes voltage clamp technique was performed to investigate neurotransmitter induced currents after mouse brain mRNA was injected into Xenopus oocytes. It was found that there were kinds of neurotransmitter receptors expressed in Xenopus oocytes besides native muscarine receptor in oocyte itself. The responses induced by neurotransmitters were divided into three kinds of types: oscillatory, smooth and compound. The receptor constituted a compounding with the channels in smooth response, agonist opened itself channel. The oscillatory response was mediated by second messenger, in which phosphoinositide metabolism and calcium liberation lead to the opening of chloride channels on the membrane. The compound responses had both of two responses.