Pranidipine enhances relaxation produced by endothelium-derived relaxing factor in carotid artery
Autor: | Hiromichi Takano, Makoto Koshita, Yoko Nakahira, Hikaru Suzuki |
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Rok vydání: | 1999 |
Předmět: |
Male
Nitroprusside Dihydropyridines Endothelium Arginine Muscle Relaxation Vasodilator Agents Guinea Pigs Indomethacin Vasodilation In Vitro Techniques Nitric Oxide Nitroarginine Muscle Smooth Vascular Membrane Potentials Norepinephrine chemistry.chemical_compound Quinoxalines medicine Animals Vasoconstrictor Agents Enzyme Inhibitors Pharmacology Oxadiazoles Dose-Response Relationship Drug Chemistry Endothelium-derived relaxing factor Hyperpolarization (biology) Calcium Channel Blockers Acetylcholine Carotid Arteries medicine.anatomical_structure Pranidipine Anesthesia Potassium Biophysics Sodium nitroprusside Muscle Contraction medicine.drug |
Zdroj: | European Journal of Pharmacology. 385:191-197 |
ISSN: | 0014-2999 |
Popis: | The effects of pranidipine, a novel dihydropyridine-type Ca 2+ -channel antagonist, on acetylcholine-induced endothelium-dependent relaxation were investigated in isolated carotid artery of the guinea-pig. In arteries contracted with high-K + solution ([K + ] 0 =28.8 mM) containing noradrenaline, the relaxation was inhibited by N ω -nitro- l -arginine, indicating an involvement of endothelium-derived relaxing factor. Pranidipine (10 −9 –10 −7 M) augmented the relaxation in a concentration-dependent manner. Sodium nitroprusside produced a relaxation in arteries contracted with high-K + solution containing noradrenaline, in an endothelium-independent manner, and the relaxation was enhanced by pranidipine. 1 H -[1,2,4] oxadiazolo [4,3- a ] quinoxalin-l-one (ODQ), an inhibitor of nitric oxide-sensitive guanylate cyclase, attenuated the relaxation produced by acetylcholine or sodium nitroprusside. In the presence of ODQ, pranidipine did not enhance the acetylcholine-induced relaxation. The relaxation produced by endothelium-derived hyperpolarizing factor was inhibited by pranidipine, with no alteration of the hyperpolarization. Thus, pranidipine augments the nitric oxide-induced relaxation, possibly by enhancing the mechanisms related to cyclic GMP. |
Databáze: | OpenAIRE |
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