title: Mode of action of coronary arterial relaxation by prostacyclin.
abstract: Subsequent to previous observations suggesting a close association between the relaxing actions of PGI2 and its increasing effects on cyclic AMP levels in bovine coronary smooth muscle, evidence indicative of a transmitter function of cAMP in PGI2-induced relaxation is presented, by showing that a) in time course experiments in circular strips of bovine coronary arteries the increase in cAMP-levels caused by PGI2 preceded the mechanical response, b) the relaxant as well as cAMP-increasing effects produced by PGI2 were significantly potentiated by the PDE-inhibitor MIX, and c) in a particulate preparation of bovine coronary arteries PGI2 concentration dependently stimulated adenylate cyclase in the presence of GTP.
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D002417:Cattle; D003331:Coronary Vessels / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism*; D011464:Epoprostenol / Q000494:pharmacology*; D006160:Guanosine Triphosphate / Q000494:pharmacology; D006168:Guinea Pigs; D007700:Kinetics; D009119:Muscle Contraction / Q000187:drug effects*; D009126:Muscle Relaxation / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism*; D011453:Prostaglandins / Q000494:pharmacology*
chemical_list: D011453:Prostaglandins; D006160:Guanosine Triphosphate; D011464:Epoprostenol; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D015056:1-Methyl-3-isobutylxanthine