ACUTE EFFECTS OF ORAL AND INTRAVENOUS ETHANOL ON RAT HEPATIC ENZYME-ACTIVITIES

Oral administration of ethanol (3 ml of 95% in 12 ml total volume over a 2 day period) significantly decreased plasma glucose and insulin levels and the activities of 2 key gluconeogenic enzymes, pyruvate carboxylase (pyruvate: CO2 ligase (ADP), EC 6.4.1.1) and fructose diphosphatase, (D-Fru[fructose]-1,6-P2 [bisphosphate] 1-phosphohydrolase, EC 3.1.3.11), and 1 glycolytic enzyme, fructose-1,6-P2 aldolase (Fru-1,6-P2 D-glyceraldehyde-3-P lyase, EC 4.1.2.13). In each instance, the administration of 2400 .mu.g daily of oral folate in conjunction with the ethanol prevented these alterations in carbohydrate metabolism. I.v. injection of ethanol produced a rapid decrease (within 10-15 min) in the activities of hepatic phosphofructokinase, (ATP:D-fructose-6-phosphate 6-phosphotransferase, EC 2.7.1.11), pyruvate kinase, (ATP: pyruvate phosphotransferase, EC 2.7.1.40), fructose diphosphatase and fructose-1,6-P2 aldolase. I.v. ethanol significantly increased hepatic cyclic AMP concentration approximately 60% within 10 min, while oral ethanol did not alter hepatic cyclic AMP concentrations. These data confirm the known antagonism between ethanol and folate and suggest that oral folate might offer a protective effect against hypoglycemia in rats receiving ethanol.