5‐HT₄‐elicited positive inotropic response is mediated by cAMP and regulated by PDE3 in failing rat and human cardiac ventricles

Abstract

5-HT(4) receptor-mediated positive inotropic responses in failing rat ventricle were cAMP-dependent. PDE3 was the main PDE regulating this response and involvement of PDE4 was disclosed by concomitant inhibition of PDE3 in both postinfarction rat and failing human hearts. 5-HT, PDE3 and PDE4 may have pathophysiological functions in heart failure.