title: Effects of norepinephrine on BAY K-8644-induced contraction in porcine coronary artery.
abstract: BAY K-8644 is a dihydropyridine calcium agonist which produces contraction in several isolated vascular preparations--including porcine coronary artery. This study examined the ability of norepinephrine to relax porcine coronary artery previously contracted with BAY K-8644 and compared this to effects on preparations contracted with histamine. Norepinephrine relaxed BAY K-8644 and histamine-treated preparations to approximately base line developed tension. The ED50 value for norepinephrine was the same in the presence of increasing concentrations of either BAY K-8644 or histamine.
mesh_terms: D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology*; D000818:Animals; D003331:Coronary Vessels / Q000187:drug effects; D006632:Histamine / Q000494:pharmacology; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology*; D013552:Swine
chemical_list: D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D006632:Histamine; D009638:Norepinephrine