ACETYLCHOLINE ACTIVATES NONSELECTIVE CATION CHANNELS IN GUINEA-PIG ILEUM THROUGH A G-PROTEIN
ACETYLCHOLINE ACTIVATES NONSELECTIVE CATION CHANNELS IN GUINEA-PIG ILEUM THROUGH A G-PROTEIN
复制标题
DOI：
10.1152/ajpcell.1990.258.6.c1173
复制
发表时间：
1990-06-01
影响因子：
--
通讯作者：
ISENBERG, G
中科院分区：
文献类型：
--
作者：
INOUE, R;ISENBERG, G
乙酰胆碱（ACh）通过激活非选择性阳离子通道（G. D. Benham，T. B。博尔顿和R. J. Lang自然伦敦316：345-347，1985; R.井上K. Kitamura和H.栗山410：69-74，1987）。在这里，我们提出的证据表明，占领毒蕈碱受体乙酰胆碱耦合通道激活通过G蛋白;耦合可以被百日咳毒素或细胞内鸟苷5 '-O-（2-硫代二磷酸）（GDP β S），而细胞内鸟苷5'-O-（3-硫代三磷酸）（GTP γ S）激活通道在乙酰胆碱的情况下。由乙酰胆碱或GTP γ S激活的电流是非加性的，传导钠离子，并且在其电压依赖性和胞质溶胶中亚微摩尔钙离子的促进作用方面是相似的。
Acetylcholine (ACh) depolarizes the membrane of mammalian intestinal myocytes by activating a nonselective cation channel (G. D. Benham, T. B. Bolton, and R. J. Lang. Nature Lond. 316: 345-347, 1985; R. Inoue, K. Kitamura, and H. Kuriyama. Pfluegers Arch. 410: 69-74, 1987). Here, we present evidence that occupation of the muscarinic receptor by ACh couples to channel activation via a G protein; the coupling can be blocked by pertussis toxin or by intracellular guanosine 5'-O-(2-thio-diphosphate) (GDP beta S), whereas intracellular guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S) activates the channel in the absence of ACh. The currents, activated by either ACh or GTP gamma S, are nonadditive, conduct sodium ions, and are similar in their voltage dependence and facilitation by submicromolar calcium ions in the cytosol.