Effects of the enantiomers of the dihydropyridine derivative 202-791 on contractility, coronary flow and ischemia-related arrhythmias in rat heart.
The (+)-enantiomer of the dihydropyridine 202-791 produced coronary constrictor and positive inotropic effects in Langendorff-perfused rat hearts whereas (--)-202-791 showed coronary dilator and negative inotropic effects. Both enantiomers showed the vascular effects at lower concentrations than the myocardial effects. Furthermore, the (+)-enantiomer significantly increased whilst the (--)-enantiomer reduced the number of ventricular ectopic beats occurring during coronary ligation. Arrhythmia-enhancing effects must therefore be considered when the potential therapeutic uses of calcium channel activators are discussed.
D000818:Animals; D001145:Arrhythmias, Cardiac / Q000209:etiology / Q000503:physiopathology*; D003326:Coronary Circulation / Q000187:drug effects*; D003327:Coronary Disease / Q000150:complications / Q000503:physiopathology*; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D013237:Stereoisomerism