Effects of intracoronary Bay k 8644, a calcium channel agonist, in anesthetized dogs. J Cardiovasc Pharmacol 1986;8(6):1223-8
Date
11/01/1986Pubmed ID
2434750DOI
10.1097/00005344-198611000-00019Scopus ID
2-s2.0-0022970489 (requires institutional sign-in at Scopus site) 5 CitationsAbstract
Bay k 8644, a new dihydropyridine calcium channel activator has been shown to have positive inotropic and vasoconstrictor properties following intravenous (i.v.) administration. In the present study, intracoronary administration of Bay k 8644 was used to isolate drug effects on regional myocardial blood flow and contractility independent of systemic hemodynamic actions in beta-adrenoceptor-blocked anesthetized dogs. Intracoronary infusion of Bay k 8644 (1.5, 3.7, 7.4, 14.8 micrograms/min) produced significant increases in contractility (percentage of segment shortening) in the drug-perfused region. Peak positive dP/dt, an index of global contractility, was increased in parallel with increases of regional contractility. No other changes in systemic hemodynamics occurred. Transmural tissue blood flow distribution as measured by radioactive microspheres was also unchanged by Bay k 8644. Intracoronary infusion of KB-944, a nondihydropyridine calcium channel blocking agent, increased coronary blood flow and decreased regional segment shortening and peak positive dP/dt. KB-944 inhibited increases in contractility produced by Bay k 8644. Thus, Bay k 8644 was shown to have a direct positive inotropic effect in vivo which was inhibited by calcium channel blockade.
Author List
Pelc LR, Gross GJ, Brooks HL, Warltier DCMESH terms used to index this publication - Major topics in bold
3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl esterAnesthesia
Animals
Benzothiazoles
Calcium Channel Blockers
Coronary Circulation
Coronary Vessels
Dogs
Female
Hemodynamics
Injections, Intravenous
Ion Channels
Male
Myocardial Contraction
Thiazoles
