Norepinephrine-Induced Phosphorylation of a 25 kd Phosphoprotein in Rat Aorta Is Altered in Intraperitoneal Sepsis.

摘要

An attenuation of the contractile response to norepinephrine (NE) has been previously demonstrated in rat aorta during intraperitoneal sepsis and endotoxemia. In this study, we determined whether NE-induced protein phosphorylation is altered in septic rat aorta as compared to control rat aorta. We found that the NE-induced phosphorylation of a 25 kd phosphoprotein was decreased. NE increased phosphorylation of the 25 kd band by 54% in the control aorta by only 12% in the septic aorta. Pyrophosphate gel purification of phosphorylated myosin showed that this 25 kd band was not related to the myosin-phosphorylated (P) light chain. These results further document that intrinsic alterations occur in the NE-mediated signal transduction system in rat aorta during sepsis and that such alterations could contribute to depressed aortic contractility. Keywords: Protein phosphorylation; Protein kinase; Phosphoinositide metabolism; Receptor. Reprints. (kt)