Ergotamine enhances acetylcholine-induced relaxation in various vascular segments of rabbits.
The vasodilator response to acetylcholine and-betanechol in segments of rabbit carotid, superior mesenteric and femoral arteries preconstricted with phenylephrine and with intact endothelium was enhanced when the vessels were preincubated with ergotamine but not with ergometrine for 60 min or longer. The vasodilator response to acetylcholine and its enhancement by ergotamine were completely prevented after methylene blue pretreatment or endothelium removal. These results were taken as evidence that the potentiation by ergotamine of the vasodilator response to acetylcholine is probably due to an increased production of EDRF from the vascular endothelium.
Demirel
E
E
Department of Pharmacology, Faculty of Medicine, University of Ankara, Turkey.
Tulunay
F C
FC
Türker
R K
RK
D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D001685:Biological Factors / Q000502:physiology; D004357:Drug Synergism; D004878:Ergotamine / Q000494:pharmacology*; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009569:Nitric Oxide; D010656:Phenylephrine / Q000494:pharmacology; D011817:Rabbits; D014665:Vasodilator Agents / Q000494:pharmacology
D001685:Biological Factors; D014665:Vasodilator Agents; D010656:Phenylephrine; D009569:Nitric Oxide; D000109:Acetylcholine; D004878:Ergotamine