Effects of endothelin-1 on the myogenic contraction of canine cerebral artery in response to quick stretch
Tanaka, Y.; Shigenobu, K.; Nakayama, K.
Research Communications in Molecular Pathology and Pharmacology 109(1-2): 95-101
2001
ISSN/ISBN: 1078-0297 PMID: 11458989 Document Number: 539164
The present study was performed to investigate the effects of endothelin-1 (ET-1) on the myogenic contraction in response to mechanical stimulation in cerebral artery. Quick stretch at a rate of 10 cm/sec with the amount of 10 - 40% of the initial muscle length (=100%) produced a myogenic contraction in canine cerebral artery. ET-1 at 30 pM, which itself produces a small contraction corresponding to about 15% of the maximal response, potentiated stretch-induced contraction. By contrast, ET-1 at concentrations over 100 pM suppressed the stretch-induced tone. The potentiated component of stretch-induced tone in the presence of 30 pM ET-1 was largely attenuated by Ca2+ channel blockers, nimodipine (1 microM) or diltiazem (1 microM). These findings suggest that lower concentrations (pM range) of ET- 1 potentiates myogenic tension development of cerebral artery in response to mechanical stretch possibly via an increased Ca2+ influx through voltage-gated Ca2+ channel.