Beta,gamma-Methylene ATP but Not alpha,beta-Methylene ATP Mimicsthe Inhibitory Effect of ATP on Ventricular Automaticity

Abstract

The effects of alpha,beta- and beta,gamma-methylene ATP on ventricular automaticity induced by local injury in the right ventricle of rats pretreated with reserpine, were investigated and compared with the effects of ATP and adenosine. Beta,gamma-methylene ATP but not alpha,beta-methylene ATP mimicked the inhibitory effect of both ATP and adenosine on the spontaneous automaticity In low concentrations, adenosine was more effective than ATP. Alpha,beta-methylene ATP caused little or no effect on ventricular automaticity. The results suggest that the effect of ATP might depend on its hydrolysis into AMP/adenosine.