Enhanced spontaneous Ca2+ events in endothelial cells reflect signalling through myoendothelial gap junctions in pressurized mesenteric arteries.

ABSTRACT: Increases in global Ca(2+) in the endothelium are a crucial step in releasing relaxing factors to modulate arterial tone. In the present study we investigated spontaneous Ca(2+) events in endothelial cells, and the contribution of smooth muscle cells to these Ca(2+) events, in pressurized rat mesenteric resistance arteries. Spontaneous Ca(2+) events were observed under resting conditions in 34% of cells. These Ca(2+) events were absent in arteries preincubated with either cyclopiazonic acid or U-73122, but were unaffected by ryanodine or nicotinamide. Stimulation of smooth muscle cell depolarization and contraction with either phenylephrine or high concentrations of KCl significantly increased the frequency of endothelial cell Ca(2+) events. The putative gap junction uncouplers carbenoxolo

SUBMITTER: Kansui Y 

PROVIDER: S-EPMC2635531 | biostudies-literature | 2008 Aug

REPOSITORIES: biostudies-literature