Calcium dependent and independent endothelin-1-induced contraction of human omentum vessels.
Endothelin-1, an endothelium derived vasoconstrictor peptide, induced concentration-dependent contraction of isolated human omental resistance arteries. Pre-treatment with the calcium antagonist nicardipine or calcium depletion caused a significant reduction but did not abolish the contractile response. However, when calcium depletion was combined with pretreatment with the protein kinase C inhibitor (H7), endothelin-1 failed to produce a contraction. This study shows that a large component of endothelin-1 contraction is calcium-dependent, involving activation of dihydropyridine-sensitive voltage-dependent calcium channels but in addition there is a calcium-independent component produced by protein kinase C activation.
Watt
P A
PA
Department of Medicine, Leicester Royal Infirmary, UK.
Baker
A R
AR
Thurston
H
H
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000328:Adult; D000368:Aged; D001158:Arteries; D002118:Calcium / Q000494:pharmacology*; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D016232:Endothelins / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007546:Isoquinolines / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D009529:Nicardipine / Q000494:pharmacology; D009852:Omentum / Q000098:blood supply*; D010879:Piperazines / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000502:physiology; D014661:Vasoconstriction / Q000187:drug effects*
D015220:Calcium Channels; D016232:Endothelins; D007546:Isoquinolines; D010879:Piperazines; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D009529:Nicardipine; D011493:Protein Kinase C; D002118:Calcium