Muscle Protein Breakdown During Endotoxemia in Rats and After Treatment With Interleukin-1 Receptor Antagonist (IL-1 ra)

Abstract

The purpose of this study was to examine the effect of endotoxemia on muscle protein degradation and to test the hypothesis that muscle proteolysis during endotoxemia is regulated by interleukin-1 (IL-1). Both total and myofibrillar protein breakdown rates in incubated extensor digitorum longus muscles were increased after the subcutaneous injection of 0.1 or 1.0 mg/kg endotoxin in rats. The endotoxin-induced increase in muscle protein breakdown was blunted by IL-1 receptor antagonist, administered intraperitoneally at a total dose of 45 or 105 mg/kg. Results suggest that endotoxemia in rats gives rise to sepsislike changes in muscle protein breakdown. Increased muscle protein breakdown during endotoxemia may be regulated, at least in part, by IL-1.