[Diurnal changes in the glucose and glycogen levels of the blood and liver of rats in chronic consumption of alcohol and after its withdrawal].

Chronic ethanol ingestion by rats exerts almost no effect on the diurnal rhythms of the blood and hepatic glucose concentrations. The rhythm of liver glycogen alters substantially in ethanol-fed animals, the phase of the rhythm being shifted and the daily mean level of glycogen being reduced by a factor of 2. Much more drastic disturbances in carbohydrate metabolism occur after ethanol withdrawal than with ethanol consumption. The diurnal rhythm of liver glycogen becomes inverted in phasing, and the rhythmic amplitude reduced greatly as compared with controls. Both the blood and hepatic glucose concentrations are maintained at nearly constant levels for 18-21 h after ethanol withdrawal, but then the level of blood glucose sharply falls, while that of hepatic glucose somewhat increases. The liver cytosolic water/blood plasma water gradient of glucose 24 h after ethanol withdrawal achieves a value of 4 and remains low 24 h later. The liver glycogen level remains relatively high over the 24 h period after ethanol withdrawal despite the severe hypoglycemia, that can be a result of a limitation of the liver cell membrane permeability for glucose.