Influence of Nicorandil on Catecholamine Release in the Perfused Rat Adrenal Medulla

• 영문명: Influence of Nicorandil on Catecholamine Release in the Perfused Rat Adrenal Medulla
• 발행기관: 대한생리학회-대한약리학회
• 저자명: Young-Youp Koh Eun-Sook Lee Hae-Jeong No Seong-Chang Woo Joong-Wha Chung Yoo-Seung Seoh Dong-Yoon Li
• 간행물 정보: 『The Korean Journal of Physiology & Pharmacology』제11권 제3호, 97~106쪽, 전체 10쪽
• 주제분류: 의약학 > 의학일반
• 파일형태: PDF
• 발행일자: 2007.01.01

영문 초록

The present study was attempted to investigate the effect of nicorandil, which is an ATP-sensitive potassium (KATP) channel opener, on secretion of catecholamines (CA) evoked by cholinergic stimulation and membrane depolarization from the isolated perfused rat adrenal glands. The perfusion of nicorandil (0.3∼3.0 mM) into an adrenal vein for 90 min produced relatively dose-and time-dependent inhibition in CA secretion evoked by ACh (5.32 mM), high K⁺ (a direct membrane depolarizer, 56 mM), DMPP (a selective neuronal nicotinic receptor agonist, 100μM for 2 min), McN-A-343 (a selective muscarinic M1 receptor agonist, 100μM for 4 min), Bay-K-8644 (an activator of L-type dihydropyridine Ca^2⁢ channels, 10μM for 4 min) and cyclopiazonic acid (an activator of cytoplasmic Ca^2⁢-ATPase, 10μM for 4 min). In adrenal glands simultaneously preloaded with nicorandil (1.0 mM) and glibenclamide (a nonspecific KATP-channel blocker, 1.0 mM), the CA secretory responses evoked by ACh, high potassium, DMPP, McN-A-343, Bay-K-8644 and cyclopiazonic acid were recovered to the considerable extent of the control release in comparison with that of nicorandil-treatment only. Taken together, the present study demonstrates that nicorandil inhibits the adrenal CA secretion in response to stimulation of cholinergic (both nicotinic and muscarinic) receptors as well as by membrane depolarization from the isolated perfused rat adrenal glands. It seems that this inhibitory effect of nicorandil may be mediated by inhibiting both Ca^2⁢ influx and the Ca^2⁢ release from intracellular store through activation of KATP channels in the rat adrenomedullary chromaffin cells. These results suggest that nicorandil-sensitive KATP channels may play an inhibitory role in the regulation of the rat adrenomedullary CA secretion.

키워드

Nicorandil Glibenclamide Catecholamine release Adrenal medulla ATP-sensitive K^⁢ (KATP) channels