The optical isomers of the 1,4-dihydropyridine BAY K 8644 show opposite effects on Ca channels.
The optical isomers of the 1,4-dihydropyridine BAY K 8644 were studied in isolated rabbit aorta and heart preparations. The (-)-enantiomer has the known vasoconstricting and positive inotropic properties of the Ca agonistic compound. In contrast, its antipode shows at about 10-50 times higher concentrations the vasodilating and negative inotropic effects of Ca antagonistic drugs. It is concluded that neither simple chemical nor physical actions can be responsible for the opposite effects of Ca antagonistic and Ca agonistic dihydropyridines.
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Franckowiak
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Bechem
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Schramm
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Thomas
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007473:Ion Channels / Q000187:drug effects*; D009200:Myocardial Contraction / Q000187:drug effects; D009543:Nifedipine / Q000031:analogs & derivatives* / Q000494:pharmacology; D010210:Papillary Muscles / Q000187:drug effects; D011817:Rabbits; D013237:Stereoisomerism; D014661:Vasoconstriction / Q000187:drug effects
D007473:Ion Channels; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D009543:Nifedipine; D002118:Calcium