胰高血糖素对大鼠腹内侧下丘脑切片神经元兴奋性突触后电位的突触前易化作用。

Presynaptic facilitation of excitatory postsynaptic potential by glucagon in neurons of rat ventromedial hypothalamic slices.

作者信息

Shoji S, Akasu T, Nonaka K

机构信息

Department of Physiology, Kurume University School of Medicine, Japan.

出版信息

Neurosci Lett. 1992 Apr 27;138(2):291-4. doi: 10.1016/0304-3940(92)90936-2.

DOI:10.1016/0304-3940(92)90936-2

PMID:1319013

Abstract

Intracellular recordings were made from neurons in rat ventromedial hypothalamus (VMH), in vitro. Application of glucagon (100 nM to 5 microM) for 2-5 min increased the amplitude of excitatory postsynaptic potential (EPSP) lasting for 10-20 min. Forskolin and 8-bromo-cyclic AMP mimicked glucagon in producing a long-lasting facilitation of the EPSP. These drugs did not affect depolarizing response produced by glutamate. 3-Isobutyl-1-methylxanthine (IBMX) potentiated the time course of glucagon-induced facilitation of the EPSP. These results suggest that glucagon facilitates the EPSP probably by increasing transmitter release through activation of adenylate cyclase.

摘要

在体外对大鼠腹内侧下丘脑（VMH）的神经元进行细胞内记录。应用胰高血糖素（100 nM至5 microM）2 - 5分钟可增加兴奋性突触后电位（EPSP）的幅度，持续10 - 20分钟。福斯高林和8 - 溴环磷酸腺苷在产生EPSP的持久易化方面模拟了胰高血糖素。这些药物不影响谷氨酸产生的去极化反应。3 - 异丁基 - 1 - 甲基黄嘌呤（IBMX）增强了胰高血糖素诱导的EPSP易化的时间进程。这些结果表明，胰高血糖素可能通过激活腺苷酸环化酶增加递质释放来促进EPSP。