Dissociation of cAMP changes and myocardial contractility in taurine perfused rat heart

Abstract

It has been determined that the inotropic effects of taurine in the rat heart are not necessarily mediated through changes in cyclic nucleotide levels. Taurine caused a transient 2-fold decrease in cAMP levels, and this was accompanied by a slight (5%), but significant positive inotropic effect. This cannot be explained by an antagonism of cAMP levels by 3′, 5′ -guanosine monophosphate (cGMP), since the latter remained essentially unchanged. Epinephrine, as is known, caused a rapid increase in cAMP levels. Perfusion with both taurine and epinephrine increased cAMP levels to the same extent as perfusion with epinephrine alone.