Contribution of chloride channel activation to the elevated muscular tone of the pulmonary artery in monocrotaline-induced pulmonary hypertensive rats.
Jpn J Pharmacol
; 86(3): 310-5, 2001 Jul.
Article
in En
| MEDLINE
| ID: mdl-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.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Monocrotaline
/
Chloride Channels
/
Hypertension, Pulmonary
/
Muscle Tonus
Limits:
Animals
Language:
En
Journal:
Jpn J Pharmacol
Year:
2001
Document type:
Article
Affiliation country:
Japón