Effect of ethanol on insulin-stimulated glucose uptake in the isolated rat diaphragm

Insulin-stimulated (0.16 and 2.56 nM) glucose uptake (GU) was studied in isolated rat diaphragms in the presence of ethanol (EtOH) 21, 42 and 84 mM as well as in diaphragms removed from rats orally treated with the drug (1.5 or 4.5 g/kg/day) for 10 or 30 days. In spite of inhibiting the base-line GU, the addition of EtOH to the incubation medium gave rise to a potentiation of the insulin effect. In the orally intoxicated series, the low-dose EtOH increased the response to 0.16 nM insulin after 10 or 30 days, no changes being observed in that induced by 2.56 nM insulin. On the other hand, the high-dose EtOH caused an increase of the base-line GU which remained practically unmodified in the presence of insulin. The precise molecular basis for these phenomena is unknown.