Liver glycogen synthase and phosphorylase changes in vivo with hypoxia and anesthetics

Methods for obtaining and processing rat liver for determination of glycogen phosphorylase a and synthase I activity were studied. An extremely rapid and profound increase in phosphorylase was induced by hypoxia. The effect on synthase I was slower and less striking. Using α- and β-adrenergic antagonists, a catecholamine-depleting agent, and a ganglionic blocking agent, it was determined that adrenergic stimulation secondary to the surgical procedure required to obtain the liver was not a significant factor. The anesthetic agent used also had a significant effect on the proportion of phosphorylase in the a form. Seconal anesthesia resulted in lower phosphorylase a levels than did ether or urethan anesthesia.