Interleukin-1 receptor antagonist attenuates sepsis-induced alterations in the igf system and protein synthesis. Lang, Charles H., Jie Fan, Robert Cooney, Thomas C. Vary. Division of Surgical Research, Department of Surgery, State University of New York at Stony Brook, Stony Brook, NY 11794-8191 and Department of Surgery, and Department of Cellular and Molecular Physiology, Pennsylvania State University, College of Medicine, Hershey, PA 17033
APStracts 2:0239E, 1995.
The purpose of the present investigation was to determine whether endogenously produced interleukin (IL)-1 mediates the changes in insulin-like growth factor (IGF)-I and IGF binding proteins (IGFBPs) induced by chronic abdominal sepsis in rats, and to correlate the changes in the IGF system with the alterations in protein synthesis. A constant infusion of IL-1 receptor antagonist (IL-1ra) was begun after the induction of sepsis and continued for 5 days. Sepsis decreased IGF-I levels in the blood, liver and gastrocnemius muscle, increased content in kidney, and did not alter IGF-I levels in heart, jejunum and spleen. IL-1ra attenuated the sepsis-induced decrease in plasma IGF-I, and completely prevented the changes in IGF-I observed in liver, kidney and the gastrocnemius. IGFBP-1 was increased in the blood, liver and muscle of septic rats. IL-1ra prevented this increase in IGFBP-1 in blood and liver, but not muscle. The rate of in vivo protein synthesis was decreased in the gastrocnemius and kidney, and unaltered in the heart, liver, jejunum and spleen. A strong linear correlation existed between levels of IGF-I and the rate of protein synthesis determined simultaneously in the gastrocnemius. These results provide evidence for the role of IL-1 as an endogenous mediator of the sepsis-induced changes in IGF-I and IGFBP-1, and suggest that the accompanying changes in muscle protein synthesis are partially mediated via changes in IGF-I.

Received 10 August 1995; accepted in final form 4 October 1995.
APS Manuscript Number E380-5.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 8 December 95