Influence of contractile agonists on the mechanism of endothelium-dependent relaxation in rat isolated mesenteric artery.
This study demonstrates directly that the relative contribution of nitric oxide (NO) and an NO synthase-independent repolarization to acetylcholine-evoked relaxation in rat isolated mesenteric resistance arteries is determined by the processes which mediate pre-contraction. Noradrenaline-induced contractions were reversed by acetylcholine via both NO and NO synthase-independent smooth muscle repolarization. In contrast, reversal of contractions to the thromboxane-mimetic, U46619, by acetylcholine was entirely mediated by the actions of NO, independently of a change in membrane potential.
Plane
F
F
Department of Pharmacology, University of Bristol.
Garland
C J
CJ
D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D004347:Drug Interactions; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D017538:Mesenteric Artery, Superior / Q000187:drug effects / Q000502:physiology; D009119:Muscle Contraction / Q000187:drug effects* / Q000502:physiology; D009126:Muscle Relaxation / Q000187:drug effects* / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000502:physiology*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009543:Nifedipine / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D019335:Nitroarginine / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D011450:Prostaglandin Endoperoxides, Synthetic / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013268:Stimulation, Chemical; D013928:Thromboxane A2 / Q000031:analogs & derivatives / Q000494:pharmacology; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology
D004791:Enzyme Inhibitors; D011450:Prostaglandin Endoperoxides, Synthetic; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D019335:Nitroarginine; D013928:Thromboxane A2; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D019001:Nitric Oxide Synthase; D009543:Nifedipine; D000109:Acetylcholine; D019331:NG-Nitroarginine Methyl Ester; D009638:Norepinephrine