FISH-OIL FEEDING IMPROVES MUSCLE GLUCOSE-UPTAKE IN TUMOR NECROSIS FACTOR-TREATED RATS

This study was conducted to characterize the effects of fish oil and s unflower oil on hepatic glucose production and peripheral glucose util ization during infusion of saline or tumor necrosis factor (TNF), usin g the euglycemic-hyperinsulinemic clamp technique combined with a prim ed-constant tracer infusion of high-performance liquid chromatography- purified H-3-3-glucose for estimation of whole-body glucose appearance and utilization rates. Insulin 10 mU/kg . min was infused to reach a plasma insulin level of 200 mu U/mL. C-14-1-deoxyglucose (C-14-DG) upt ake was also measured in specific tissues following intravenous bolus administration. The results showed that during a hyperinsulinemic-eugl ycemic clamp. infusion of TNF 20 mu g/kg for 3 hours resulted in a sig nificant reduction of glucose infusion and a significant increase of h epatic glucose production in both dietary groups as compared with sali ne infusion. indicating a state of insulin resistance induced by TNF. The results also showed that TNF infusion significantly decreased the rate of C-14-DG uptake in muscle in the sunflower oil group but not in the fish oil group, suggesting that fish oil is able to restore to no rmal the glucose utilization impaired by TNF. These observations sugge st that in hyperinsulinemic and euglycemic conditions, prefeeding with fish oil significantly improves glucose uptake in muscle tissue, but does not alter the increase in hepatic glucose production during TNF i nfusion. Copyright (C) 1995 by W.B. Saunders Company