Cyclic AMP and Intestinal Glycoprotein Synthesis: The Effect of β-Adrenergic Agents, Theophylline, and Dibutyryl Cyclic AMP

Abstract

Incorporation of [1-14C]glucosamine by acid-precipitable protein was enhanced in intestinal slices by isoproterenol, epinephrine, theophylline, and dibutyryl cyclic AMP. Moreover, the effect of either isoproterenol or epinephrine on [1-14C]glucosamine incorporation was markedly potentiated by the addition of theophylline. Uptake of [1-14C]glucosamine into the acid-soluble compartment of intestinal slices was not significantly affected by isoproterenol, epinephrine, or theophylline.The stimulatory effect of isoproterenol and theophylline was completely inhibited by cycloheximide. Subfractionation of intestinal slice homogenates indicated that increased synthesis was not confined to one glycoprotein class but appeared to effect mucins and glycocalyx glycoproteins equally. These results indicate that β-adrenergic hormones and cyclic AMP stimulate intestinal glycoprotein synthesis and may control the production of glycoproteins located at the intestinal surface.