Cardiodepressant effects of ethanol on guinea-pig atria: presynaptic and postsynaptic components.
Ethanol, at concentrations ranging from 0.5 to 1.5%, depressed myocardial contractility of electrically-stimulated guinea-pig atria. This effect was evident in preparations bathed with a low calcium concentration, but was progressively reduced by increasing the extracellular calcium. The same concentrations of ethanol produced a dose-dependent inhibition of the cardiac response to field stimulation of the adrenergic nerve terminals. This effect was again calcium-dependent. These results support the hypothesis that the pre- and postsynaptic components of the cardiodepressant effects of ethanol are due to a reduction in calcium availability both at the nerve endings and in the contractile cells.
Mantelli
L
L
Corti
V
V
Ledda
F
F
D000818:Animals; D000889:Anti-Arrhythmia Agents; D004558:Electric Stimulation; D000431:Ethanol / Q000494:pharmacology*; D006168:Guinea Pigs; D006321:Heart / Q000294:innervation*; D066298:In Vitro Techniques; D009200:Myocardial Contraction / Q000187:drug effects; D009474:Neurons / Q000187:drug effects; D013569:Synapses
D000889:Anti-Arrhythmia Agents; D000431:Ethanol