pH-dependent release of EDRF from rabbit aortic endothelium.
Rabbit aortic strips superfused with Krebs buffer pH 7.3 were relaxed in an endothelium-dependent manner by both acetylcholine (0.01-0.3 microM) and an increase in pH up to 7.6-8.5. These vasorelaxant effects were abrogated by methylene blue (50 microM), lidocaine (1.3-640 microM) and verapamil (2.5-5.0 microM). Nitrendipine (2.5-5.0 microM) abolished only acetylcholine-induced, but not pH-induced relaxations. It is concluded that activation of Na+/H+ exchange might be involved in triggering the release of an endothelium-derived relaxing factor.
Dembińska-Kieć
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A
Department of Pharmacology, N. Copernicus Academy of Medicine, Kraków, Poland.
Zmuda
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A
Gryglewski
R J
RJ
D000109:Acetylcholine / Q000037:antagonists & inhibitors; D000818:Animals; D001013:Aorta, Thoracic / Q000378:metabolism; D001639:Bicarbonates / Q000037:antagonists & inhibitors; D004730:Endothelium, Vascular / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008012:Lidocaine / Q000494:pharmacology; D009568:Nitrendipine / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D011817:Rabbits; D012964:Sodium / Q000037:antagonists & inhibitors; D017693:Sodium Bicarbonate; D014700:Verapamil / Q000494:pharmacology
D001639:Bicarbonates; D009569:Nitric Oxide; D017693:Sodium Bicarbonate; D008012:Lidocaine; D009568:Nitrendipine; D012964:Sodium; D014700:Verapamil; D000109:Acetylcholine