PREVENTION OF SKELETAL-MUSCLE CATABOLISM IN SEPSIS DOES NOT IMPAIR VISCERAL PROTEIN-METABOLISM

We investigated whether the preservation of gastrocnemius protein by i nterleukin-l receptor antagonist (IL-1ra) during sepsis altered protei n metabolism in visceral tissues. Sepsis was induced by creation of an abdominal abscess followed by infusion of saline or IL-1ra. Five days later, the tissue protein content and rate of protein synthesis were measured. IL-1ra did not significantly alter hepatic protein metabolis m in septic or control animals. In kidney, the protein content and rat e of protein synthesis were both decreased by sepsis and significantly ameliorated by the infusion of IL-1ra. Sepsis decreased the rate of p rotein synthesis in the small intestine. IL-1ra increased intestinal p rotein synthesis in both control and septic animals; however, the effe cts were localized to the seromuscular layer. The preservation of musc le protein by IL-1ra in sepsis did not adversely affect protein synthe sis in any of the visceral tissues examined. IL-1 appears to mediate t he sepsis-induced changes in protein synthesis in kidney and small int estine but not in liver or spleen. Protein synthesis in each visceral organ responds differently to the septic insult and modulation of IL-1 bioactivity.