Increased glucose metabolism by epitrochlearis muscle removed from endotoxin-treated rats

In this study glucose metabolism was assessed in epitrochlearis muscle taken from control and endotoxin-treated rats. Endotoxin (1 mg/100 g) or saline was administered i.v. to rats and the epitrochlearis muscle was removed 3 hr later for in vitro incubation. Glycolysis, determined as 3H2O production from [2-3H]-glucose, was increased 45% in muscle taken from endotoxin-treated rats compared to control animals. Glycogen synthesis, assessed by the incorporation of [U-14C]-glucose into glycogen, was similarly elevated. Glycolysis and glycogen synthesis were stimulated by insulin in a dose-dependent manner. Muscles removed from endotoxin-treated rats were slightly more sensitive to insulin, but at the highest dose of insulin used, differences between muscles from control and endotoxemic rats remained similar to differences seen without insulin. Endotoxin-induced changes in glucose metabolism were not reversed by the presence of indomethacin, indicating that prostaglandin production is not responsible for these changes. Thus, endotoxemia results in changes in glucose metabolism in skeletal muscle that are retained in vitro in the absence or presence of insulin.