Effect of calcium antagonists on endothelin-induced contraction of isolated human resistance arteries: differences related to site of origin.
Small resistance arteries were isolated from human subcutaneous fat and omentum and studied using a myograph. Endothelin-1 induced a concentration-dependent contraction in both type of arteries. In subcutaneous arteries preincubation with calcium antagonists partially inhibited responses to endothelin-1. The effectiveness of the calcium antagonists was nisoldipine > nimodipine > verapamil = flunarizine > diltiazem. In omental arteries nimodipine and diltiazem had no significant effect on endothelin-1-induced contraction and removal of extracellular calcium also had little effect on responses to endothelin-1. The role of influx of extracellular calcium through voltage operated calcium channels in endothelin-1-induced contraction appear to differ between subcutaneous and omental resistance arteries.
Department of Clinical Pharmacology and Therapeutics, St. Mary's Hospital Medical School, Paddington, London, UK.
W
W
Sunman
G
G
Martin
W M
WM
Hair
P S
PS
Sever
A D
AD
Hughes
D000273:Adipose Tissue / Q000098:blood supply*; D000328:Adult; D000368:Aged; D001158:Arteries / Q000187:drug effects / Q000502:physiology*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D015220:Calcium Channels / Q000502:physiology; D004110:Diltiazem / Q000494:pharmacology; D016232:Endothelins / Q000494:pharmacology*; D005444:Flunarizine / Q000494:pharmacology; D006801:Humans; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D008875:Middle Aged; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology; D009213:Myography; D009553:Nimodipine / Q000494:pharmacology; D015737:Nisoldipine / Q000494:pharmacology; D009852:Omentum / Q000098:blood supply*; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology*; D014700:Verapamil / Q000494:pharmacology
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D016232:Endothelins; D015737:Nisoldipine; D009553:Nimodipine; D014700:Verapamil; D004110:Diltiazem; D005444:Flunarizine