Relative and combined roles of ethanol and protein malnutrition on muscle zinc, potassium, copper, iron, and magnesium.

The aim of the present study is to analyse the relative and combined effects of ethanol and protein malnutrition on muscle zinc, copper, iron, potassium, and magnesium 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 2 months later, and was studied both chemically and histochemical-morphometrically. Both muscle zinc and potassium, but not copper nor iron nor magnesium, were significantly decreased in the protein-deprived, ethanol-fed animals, the main effect of these variations being attributable to ethanol rather than to protein deprivation. However, coexisting protein deprivation aggravated the decrease in both muscle zinc and potassium. Both muscle zinc and potassium were significantly related to serum albumin, weight loss, and type IIb fibre atrophy; and muscle zinc, in addition, to the decrease in type IIb fibre proportion. Therefore, a decrease in muscle content of both elements is related to histochemical-morphometrical changes observed in alcoholic myopathy. In addition, both ethanol and protein deficiency exerted independent, highly significant effects both on type IIb fibre atrophy and proportion.