title: Antagonism between adenosine and bromobenzoyl-methyladamantylamine, a K+-channel blocker, in atrial myocardium of guinea pig.
abstract: The effect of bromobenzoyl-methyladamantylamine (BMA) on the adenosine-induced changes in the electrical and mechanical activity of the atrial muscle, and the effect of adenosine on the slow action potentials induced by BMA in K+-depolarized atrial myocardium of guinea pig were studied. BMA was able to antagonize the adenosine-induced shortening of the action potential duration and negative inotropic effect. This action of BMA was potentiated by theophylline, and reduced by dipyridamole. Adenosine depressed the BMA-induced slow action potentials. The results suggest that there may be an antagonism between BMA and adenosine.
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000241:Adenosine / Q000037:antagonists & inhibitors*; D000547:Amantadine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D016275:Atrial Function; D003864:Depression, Chemical; D006168:Guinea Pigs; D006321:Heart / Q000502:physiology*; D066298:In Vitro Techniques; D009200:Myocardial Contraction / Q000187:drug effects*
chemical_list: C036548:4-bromobenzoyl-methyladamantylamine; D000547:Amantadine; D000241:Adenosine