Prevention of the Negative Chronotropic Effect of Adenosine by Caffeine

Abstract

A constant pressure perfusion of the sinus node artery was performed in ten vagotomized dogs. The selective administration of adenosine, AMP, ADP or ATP into this artery caused a negative chronotropic effect which was not blocked by either atropine or tetrodotoxin, but was blocked by the continuous infusion of caffeine or theophylline. In the meanwhile atrial fibrillation was readily induced by acetylcholine.