The role of endothelium in the phenylephrine-induced oscillatory responses of rabbit mesenteric arteries.
Phenylephrine-induced oscillatory contractions in rabbit mesenteric arteries were investigated in vitro. Adrenergic, cholinergic, or histamine antagonists as well as cyclooxygenase and lipoxygenase inhibitors had no effect on this phenylephrine-induced oscillation. The removal of extracellular calcium ions or treatment with a calcium antagonist reduced the amplitude and frequency of the oscillation. Removal of the endothelium or treatment with inhibitors of the synthesis or the target enzyme of endothelium-derived relaxing factor (EDRF) also reduced the amplitude and frequency of the oscillation. In a perfusion bioassay, the perfusate from an endothelium-intact arterial segment induced oscillation of an endothelium-denuded arterial ring recipient. These results suggest that phenylephrine-induced oscillation is mediated by an endothelium-derived factor such as EDRF and depends on the influx of extracellular calcium ions.
Omote
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Development Laboratories Hirakata Center, Marion Merrell Dow K.K., Osaka, Japan.
Kajimoto
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Mizusawa
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H
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D001337:Autonomic Agents / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D006633:Histamine Antagonists / Q000494:pharmacology; D016859:Lipoxygenase Inhibitors / Q000494:pharmacology; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects* / Q000502:physiology; D008751:Methylene Blue / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology; D009569:Nitric Oxide / Q000502:physiology*; D010656:Phenylephrine / Q000494:pharmacology*; D011817:Rabbits; D019323:omega-N-Methylarginine
D001337:Autonomic Agents; D016861:Cyclooxygenase Inhibitors; D006633:Histamine Antagonists; D016859:Lipoxygenase Inhibitors; D010656:Phenylephrine; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D001120:Arginine; D002118:Calcium; D008751:Methylene Blue