Intracellular and extracellular Ca2+ regulate histamine-induced release of nitric oxide in vascular endothelial cells as shown with sensitive and selective nitric oxide electrodes.
The effects of various agents that alter the intracellular Ca2+ concentration and the extracellular Ca2+ concentration on histamine-induced release of nitric oxides (NO) from porcine aortic endothelial cells were studied using NO electrodes. The NO release induced by application of histamine (200 microM) in Ca(2+)-free solution was similar to that in solution with a normal Ca2+ concentration on its first application, but reduced on its second application. NO release was also suppressed by 1,2-bis (o-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid (BAPTA), which lowers the intracellular Ca2+ concentration, and was completely inhibited by Co2+, but it was not affected by verapamil, a voltage-dependent Ca2+ channel blocker. These results suggest that Ca2+ release from intracellular stores might play an important role in NO production, that influx of extracellular Ca2+ is required to refill the stores, and that this Ca2+ influx is not through voltage-dependent Ca2+ channels.
Kishi
F
F
Second Department of Internal Medicine, University of Tokushima, Japan.
Nakaya
Y
Y
Takahashi
A
A
Miyoshi
H
H
Nomura
M
M
Saito
K
K
D000818:Animals; D001011:Aorta / Q000187:drug effects* / Q000378:metabolism; D002118:Calcium / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D004727:Endothelium / Q000378:metabolism; D006632:Histamine / Q000494:pharmacology*; D009569:Nitric Oxide / Q000378:metabolism*; D013552:Swine; D014700:Verapamil / Q000494:pharmacology
D009569:Nitric Oxide; D004533:Egtazic Acid; D006632:Histamine; D014700:Verapamil; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium