Endothelin-induced Ca-independent contraction of the porcine coronary artery.
Front surface fluorometry and porcine coronary arterial strips loaded with fura-2 were used to investigate the effect of endothelin on cytosolic Ca concentrations, [Ca]i, and on contractile force, the objective being to elucidate the mechanism of action. Both in the presence and absence of extracellular Ca, endothelin induced rapid and dose-dependent increases in [Ca]i and in contraction. When caffeine-sensitive and histamine-sensitive intracellular Ca stores were depleted, in Ca-free medium, a transient contraction but no increase in [Ca]i followed the subsequent application of endothelin. This Ca-independent component was largely inhibited by the relative protein kinase C inhibitor, H-7, but not inhibited by W-7, calmodulin antagonist. This component is probably linked to activation of protein kinase C.
Kodama
M
M
Division of Molecular Cardiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Kanaide
H
H
Abe
S
S
Hirano
K
K
Kai
H
H
Nakamura
M
M
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology*; D003331:Coronary Vessels / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004533:Egtazic Acid / Q000494:pharmacology; D016232:Endothelins; D004730:Endothelium, Vascular; D006632:Histamine / Q000494:pharmacology; D007546:Isoquinolines / Q000494:pharmacology; D007700:Kinetics; D009119:Muscle Contraction / Q000187:drug effects*; D010455:Peptides / Q000494:pharmacology*; D010879:Piperazines / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D013050:Spectrometry, Fluorescence; D013552:Swine
D016232:Endothelins; D007546:Isoquinolines; D010455:Peptides; D010879:Piperazines; D002110:Caffeine; D004533:Egtazic Acid; D006632:Histamine; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D011493:Protein Kinase C; D002118:Calcium