β,γ-Methylene ATP but Not α,β-Methylene ATP Mimicsthe Inhibitory Effect of ATP on Ventricular Automaticity

Abstract

Abstract: The effects of α,β- and β,γ-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. β,γ-Methylene ATP but not α,β-methylene ATP mimicked the inhibitory effect of both ATP and adenosine on the spontaneous automaticity. In low concentrations, adenosine was more effective than ATP. α,β-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.