Ethanol and glycogen synthesis in cardiothoracic and skeletal muscles following glucose re-feeding after starvation in the rat.

The pattern of glycogen deposition in individual cardiothoracic and skeletal muscles in response to oral and intraperitoneal glucose administration was examined in 40 h-starved rats. Rates of glycogen synthesis were consistently higher in oxidative muscles than in non-oxidative muscles. Intragastric ethanol administration was associated with an impaired glycaemic response and the almost total abolition of glycogen deposition in oxidative muscles in response to oral or intraperitoneal glucose re-feeding. This effect was dose-dependent and differential, in that ethanol produced no equivalent impairment in glycogen deposition in non-oxidative muscles. Ethanol treatment also selectively promoted glycogenolysis in oxidative muscles in the starved state. There was positive correlation (P < 0.001) between the decrease in glycogen levels in soleus and diaphragm muscles in response to increasing ethanol doses and blood glucose and lactate concentrations after intraperitoneal glucose administration, implying that the basis for the impairment in glycogen synthesis may be diminished glucose availability. The mechanism whereby ethanol may differentially compromise carbohydrate metabolism in oxidative muscles is discussed.