Effect of Epinephrine on Monophasic Action Potential of Auricular Muscle

Abstract

The monophasic action potential of turtle auricular muscle stimulated to contract more forcibly by epinephrine remains unchanged. An antagonism exists between epinephrine and vagal stimulation both on the contraction and on the ecg. Attention is directed to the possibility of a causal relationship between membrane phenomena and contractility in vagally-inhibited auricular muscle, and the possible physical basis for the effects of acetylcholine and epinephrine on the monophasic action potential of auricular muscle.