Relative and combined roles of ethanol and protein malnutrition on skeletal muscle

The aim of the present study is to analyse the relative and combined effect of ethanol and protein malnutrition on muscle changes in ethanol-fed rats. The study was performed in 32 animals divided into four groups, fed with the Lieber-DeCarli control, 36% ethanol, 2% protein, and 36% ethanol/2% protein-containing diets, respectively. Right gastrocnemius muscle was removed two months later, and histochemical-morphometrically studied. Type IIb fibre atrophy was observed both in the alcoholic and protein-deficient animals. The combination of these factors led to a slightly more marked atrophy. Malnutrition led to a decrease in type I fibre diameter; ethanol caused an increase in their size; whereas concurrent administration of ethanol and a protein deficient diet led to type I fibre atrophy. The proportion of type IIb fibre decreased in the three experimental groups with respect to the control group, especially in the alcoholic, protein-deficient animals. Thus, malnutrition potentiates the effect of ethanol except for changes in type I fibre diameter, in which the effects are opposite.