ISSN:
1440-1681
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
1. The effect of extracellular calcium ion (Ca2+) depletion, diltiazem, D-600 and TMB-8 on potassium (K+), norepinephrine-(NE) and histamine-induced contractions of the rabbit isolated ovarian artery was studied.2. K+-induced contractions, which were biphasic, were rapidly lost (∼ 5 min) when calcium was removed from the physiological saline solution (O-Ca2+ PSS). NE and histamine-induced contractions also declined rapidly under nominal O-Ca2+ conditions without any evidence of a depletion resistant component. However, after 1 h under these conditions there was a partial restoration of their responses.3. EGTA (10-3 mol/l) abolished these contractions to NE and histamine but not those in normal PSS.4. Diltiazem and D-600 were more effective against K+-induced than NE- and histamine-induced contractions while the intracellular Ca2+ antagonist TMB-8 was equally effective against all three responses.5. Histamine could still evoke contraction of the K+-contracted ovarian artery after this had been completely abolished with diltiazem or D-600 but not TMB-8.6. These results are interpreted to suggest that K+, NE and histamine probably release intracellular Ca2+ to evoke contractions of the ovarian artery. They differ, however, in the mechanisms they employ to facilitate entry of extracellular calcium, which in turn leads to intracellular calcium release.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1440-1681.1986.tb02384.x
