Kinetics of Cyclic Adenosine Monophosphate Changes in Rat Heart following Epinephrine Administration

Direct evidence in favour of epinephrine causes glycogenolysis in cardiac muscle by a series of enzymatic reactions involving the formation of cyclic AMP is not conclusive, but a possible relation between cyclicAMP and the inotropic effect of catecholamines is also tentative.

Abstract

ALTHOUGH it has become generally accepted1 that epinephrine causes glycogenolysis in cardiac muscle by a series of enzymatic reactions involving the formation of cyclic AMP, activation of phosphorylase b kinase, and finally conversion of phosphorylase b to the active a form, direct evidence in favour of this mechanism in the intact heart is so far not conclusive2. Furthermore, a possible relation between cyclic AMP and the inotropic effect of catecholamines is also tentative.