Effects of insulin-produced hypoglycemia in combination with ethanol on spontaneous motor activity in rats

The hazardous consequences of drinking alcohol by persons receiving insulin treatment is indicated by clinical reports, but little controlled research has investigated the combination of hypoglycemia and ethanol intoxication. Ethanol's effect on spontaneous motor activity (SMA, detected by Opto-Varimax activity meters) in hypoglycemic (HG) rats was determined over a range of ethanol doses in two experiments. Combinations of insulin and ethanol were administered intraperitoneally to moderately food-deprived rats. Blood glucose was measured before and after a 30-min SMA-monitoring period. In Experiment 1, ethanol doses of 300, 600 and 1200 mg/kg were combined with insulin at doses 0.5 and 2 U/kg. A second experiment tested a narrower range of drug doses (ethanol 600 and 1200 mg/kg, insulin 1 U/kg) under slightly different procedures. After insulin treatment, blood-glucose levels dropped to approximately 40-60% of control levels and this HG was accompanied by decreased SMA. Ethanol did not influence blood-glucose levels, nor did it potentiate the HG produced by insulin. Combination of HG and the highest ethanol dose potentiated the SMA-depressant effect in both experiments, whereas lower ethanol doses partially reversed the suppression of motor activity in HG rats.