Effect of monophenolic amines on glycogen metabolism in the nerve-cord of the american cockroach, Periplaneta americana

Evidence is presented to show that octopamine is not identical with the corpus cardiacum factor causing glycogenolysis in the nerve-cord, and it is shown that the effect of tyramine or its β-hydroxylated derivativeOctopamine results from the activation of phosphorylase.

Abstract

As little as 25 nmoles of tyramine or its β-hydroxylated derivative octopamine have been shown to have a strong glycogenolytic effect on the cockroach nerve-cord in vivo. This effect results from the activation of phosphorylase. Tyramine, octopamine, and synephrine were shown to activate nerve-cord phosphorylase in vitro at concentrations as low as 5 × 10−7M. Analogues of the phenolic amines having two hydroxyl groups on the ring (the catecholamines dopamine, norepinephrine, and epinephrine) or those having no hydroxyl groups on the ring (β-phenylethylamine and β-hydroxy-β-phenylethylamine) were without effect on phosphorylase. Evidence is presented to show that octopamine is not identical with the corpus cardiacum factor causing glycogenolysis in the nerve-cord.