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PubMed · 2442401

Calcium-agonists.

M Bechem·M Schramm
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Abstract

In contrast to nifedipine-like calcium antagonists, calcium agonistic 1,4-dihydropyridines have vasoconstricting and positive inotropic properties. BAY K 8644 has become the prototype of this new class. Its enantiomers show opposite effects on the calcium channel: one acts as a calcium agonist with the pharmacological profile of the racemic compound, its antipode has calcium antagonistic effects at 10 times higher concentrations. Voltage clamp studies reveal calcium current increasing effects at 3 X 10(-8) mol/l BAY K 8644, while the current is reduced at 3 X 10(-6) mol/l. Analysis of the calcium current activation and deactivation kinetics shows that BAY K 8644 leaves the mean closed times of the calcium channel unchanged while it increases the mean open times. From these data a reaction model of drug action is derived, suggesting that BAY K 8644 binds only to the open state of the Ca-channel.

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3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl esterAnimalsCalciumHumansIon ChannelsKineticsMembrane PotentialsModels, BiologicalVasoconstrictor AgentsJournal ArticleReview

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BibTeXRIS

M Bechem, M Schramm. 1987. Calcium-agonists.. https://doi.org/10.1016/s0022-2828(87)80005-6

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