7 541

Cited 7 times in

Changes in stretch-induced tone induced by intracellular acidosis in rabbit basilar artery: Effects on BKCa channel activity

 Young-Eun Cho  ;  Duck-Sun Ahn  ;  Young-Ho Lee  ;  Michael J. Taggart  ;  Young-Hwan Kim 
 VASCULAR PHARMACOLOGY, Vol.47(1) : 74-82, 2007 
Journal Title
Issue Date
It is known that myogenic reactivity is a fundamental determinant of the relative constancy of blood flow through the cerebral artery. It is also known that acute alteration of pH significantly affects the cerebral circulation and, therefore, we investigated the effect of mechanism of action of intracellular acidosis on myogenic tone in rabbit basilar artery. Myogenic tone was developed by imposed stretch of basilar artery and intracellular acidosis induced by the bath application of 20 mmol/L sodium acetate. Sodium acetate caused a biphasic increase in myogenic tone. The initial component reached a peak quickly and then fell slowly to a lower steady-state significantly above basal tone. The sodium acetate-induced increase in myogenic tone was completely inhibited by elimination of external Ca2+, or treatment of nifedipine, but not with gadolinium or NPPB. TEA (5 mmol/L) and iberiotoxin (100 nmol/L) inhibited the sodium acetate-induced increase in myogenic tone. In inside-out patch-clamp recordings, decreasing pH of the mock intracellular solution from 7.4 to 6.9 markedly inhibited BKCa currents. Several inhibitors involved in Ca2+ sensitization pathways, 10− 6 mol/L Y-27632, 5 × 10− 7 mol/L calphostin C and 10− 5 mol/L PD98059 had no effect on the sodium acetate-induced increase in myogenic tone. These results suggest that intracellular acidosis increases stretch-induced myogenic tone in rabbit basilar artery. Furthermore, voltage-dependent Ca2+ influx plays a key role in intracellular acidosis-induced increase in myogenic tone and may be mediated, at least in part, by inhibition of BKCa.
Full Text
Appears in Collections:
1. College of Medicine (의과대학) > Dept. of Physiology (생리학교실) > 1. Journal Papers
Yonsei Authors
Kim, Young Hwan(김영환)
Ahn, Duk Sun(안덕선) ORCID logo https://orcid.org/0000-0001-9351-6951
Lee, Young Ho(이영호) ORCID logo https://orcid.org/0000-0002-5749-1045
Cho, Young Eun(조영은)
사서에게 알리기


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.