Nonsuppressible insulinlike activity (NSILA) and the glucose dyshomeostasis of agonal sepsis.

Abstract

Peritonitis was induced through the ligation and puncture of rat ceca. The rats were divided into three groups: 1) rats whose ceca were ligated and punctured (CLP); 2) rats whose ceca were isolated and replaced without being tied or perforated (SHAM); and 3) rats which were fasted but not subjected to surgery (FC). Plasma glucose levels, serum insulin content, basal and stimulated glucose oxidation rates of adipose tissue, and nonsuppressible insulinlike activity were measured at the time of death or sacrifice. CLP rats were hypoglycemic (35.9 +/- 2.7 mg/dl) at death whereas both FC and SHAM groups were normoglycemic at 101 +/- 1.6 mg/dl and 94.3 +/- 3.9 mg/dl, respectively. Terminal serum immunoreactive insulin content for the three groups did not vary from each other. The oxidation of 14C-glucose to 14CO2 by the septic rats' epididymal fat pads was significantly greater than either SHAM or FC (56.3 +/- 6.4 vs 35.0 +/- 3.3 or 24.5 +/- 2.4 X 10(3) 14CO2 dpm/g/h). When a suprastimulatory concentration of insulin (1 mU/ml) was added in vitro, the septic rats' fat pads were further stimulated to a greater glucose oxidation rate than either SHAM or FC group. Finally, nonsuppressible insulinlike activity (NSILA) was assessed by the addition of guinea pig antiinsulin serum (GPAIS) and rat sera to the in vitro preparations. CLP sera demonstrated a significantly greater NSILA level than either control group. The gathered data suggest that enhanced peripheral tissue glucose oxidation in late sepsis is associated with elevated NSILA.