Influences of changes in calcium concentrations, cocaine and clonidine on the cardiac effect of acetaldehyde in rat isolated atria.
1. Cardiovascular responses to acetaldehyde (AChO) were investigated in rat isolated atria. 2. Results show that two different doses of AChO (0.29 and 0.88 mM) induce positive inotropic effects on rat atria, and express Ca2+ dependence when analyzed at three external Ca2+ concentrations (0.6, 1.1, 2.2 mM). 3. Cocaine (3.5 and 35 microM) produced significant potentiation of the AChO-positive (0.29 and 0.88 mM) inotropic effect in 1.1 mM Ca2+ medium. 4. Clonidine (40 microM) increased the peak tension developed (PTD) induced by AChO (both 0.29 and 0.88 mM) only 1.1 mM Ca2+ medium. 5. It is suggested that the positive inotropic effect produced by AChO involves a Ca2(+)-dependent mechanism, which can be potentiated by the additional stimulation of alpha-adrenergic receptors.
Martínez
J L
JL
Department of Pharmacology, Faculty of Medicine, University of Chile, Santiago, Chile.
Penna
M
M
D000079:Acetaldehyde / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D003000:Clonidine / Q000494:pharmacology*; D003042:Cocaine / Q000494:pharmacology*; D005260:Female; D006325:Heart Atria / Q000187:drug effects*; D066298:In Vitro Techniques; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar
D000079:Acetaldehyde; D003042:Cocaine; D003000:Clonidine; D002118:Calcium