title: [Effects of trihexyphenidyl on slow action potentials in guinea pig papillary muscles].
abstract: Effects of trihexyphenidyl (THP) were examined on the slow action potentials (SAP) induced by isoproterenol (Iso), histamine (His), Bay k 8644 or tetrodotoxin (TTX), in guinea pig papillary muscles. THP 10, 50, and 100 mumol.L-1 depressed the maximal upstroke velocity (Vmax) and the action potential amplitude (APA) of SAP. These effects were reversed partially by the elevation of the concentration of calcium from 2.0 to 5.6 mmol.L-1. The results suggest that THP can inhibit calcium inflow in myocardium.
authors.affiliation: Department of Pharmacology, He-nan Medical University, Zhengzhou, China.
authors.forename: B
authors.initials: B
authors.lastname: Jiang
authors.forename: G Q
authors.initials: GQ
authors.lastname: Zhang
authors.forename: J
authors.initials: J
authors.lastname: Ke
mesh_terms: D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002118:Calcium / Q000493:pharmacokinetics; D000252:Calcium-Transporting ATPases / Q000187:drug effects; D005260:Female; D006168:Guinea Pigs; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D010210:Papillary Muscles / Q000502:physiology*; D013779:Tetrodotoxin / Q000494:pharmacology; D014282:Trihexyphenidyl / Q000494:pharmacology*
chemical_list: D013779:Tetrodotoxin; D014282:Trihexyphenidyl; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D000252:Calcium-Transporting ATPases; D007545:Isoproterenol; D002118:Calcium