Somatostatin induces hyperpolarization in pancreatic islet a cells by activating a G protein-gated K+ channel

被引：59

作者：

Yoshimoto, Y

Fukuyama, Y

Horio, Y

Inanobe, A

Gotoh, M

Kurachi, Y

机构：

[1] Osaka Univ, Fac Med, Dept Pharmacol 2, Osaka 5650871, Japan

[2] Osaka Univ, Grad Sch Med, Osaka 5650871, Japan

[3] Osaka Univ, Fac Pharmaceut Sci, Dept Pharmacol, Osaka 5650871, Japan

[4] Fukushima Med Univ, Dept Surg 1, Fukushima 9601295, Japan

来源：

FEBS LETTERS | 1999年 / 444卷 / 2-3期

基金：

日本学术振兴会;

关键词：

G protein-gated K+ channel; hyperpolarization; pancreatic alpha cell; somatostatin; patch clamp; immunohistochemistry;

D O I：

10.1016/S0014-5793(99)00076-9

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

Somatostatin inhibits glucagon-secretion from pancreatic alpha cells but its underlying mechanism is unknown. In mouse alpha cells, we found that somatostatin induced prominent hyperpolarization by activating a K+ channel, which was unaffected by tolbutamide but prevented by pre-treating the cells with pertussis toxin, The K+ channel was activated by intracellular GTP (with somatostatin), GTP gamma S or G beta gamma subunits. It was thus identified as a G protein-gated K+ (K-G) channel. RT-PCR and immunohistochemical analyses suggested the K-G channel to be composed of Kir3.2c and Kir3.4. This study identified a novel ionic mechanism involved in somatostatin-inhibition of glucagon-secretion from pancreatic alpha cells. (C) 1999 Federation of European Biochemical Societies.

引用

页码：265 / 269

页数：5

共 29 条

[1] DOES GALANIN INHIBIT INSULIN-SECRETION BY OPENING OF THE ATP-REGULATED K+ CHANNEL IN THE BETA-CELL [J].