Referenced in: none

Automatically associated channels: ClC3 , ClC4

Title: Contribution of chloride channel activation to the elevated muscular tone of the pulmonary artery in monocrotaline-induced pulmonary hypertensive rats.

Authors: H Nakazawa, M Hori, T Murata, H Ozaki, H Karaki

Journal, date & volume: Jpn. J. Pharmacol., 2001 Jul , 86, 310-5

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/11488431

Abstract
In monocrotaline-treated rat pulmonary artery from which endothelium was removed, greater spontaneous muscular tone was observed under resting conditions than in vehicle-treated artery. The aim of the present study was to show the possible contribution of Cl- channels in the mechanism of the elevated tone. Verapamil almost completely inhibited the elevated spontaneous muscular tone by decreasing [Ca2+]i. The elevated muscular tone was also inhibited by 4,4'-diisothiocyanato-stilbene-2,2'-disulfonic acid (DIDS), a Cl- channel inhibitor. After the inhibition of muscular tone by DIDS, verapamil did not induce further relaxation. Quantitative RT-PCR analysis indicated that the mRNA levels of ClC3 and Ca2+-activated Cl- channels did not change in the pulmonary hypertensive pulmonary artery from those of vehicle-treated rats. These results suggest that the elevated muscular tone observed in the monocrotaline-induced hypertensive pulmonary artery is due to membrane depolarization of smooth muscle cells and that this phenomenon might be mediated by the activation of DIDS-sensitive Cl- channels.