Alcoholic muscle disease: features and mechanisms

Abstract

Approximately 50 per cent of all chronic alcohol misusers have alcoholic muscle disease. Chronic alcoholic skeletal muscle myopathy is characterized by a selective atrophy of type II fibres, so that up to 20 per cent of the entire skeletal musculature is lost. The pathogenetic mechanism for the myopathy is currently unknown but a model has been described in which various anatomically-distinct skeletal muscles are employed to reflect type I and II fibres, i.e. the soleus and plantaris, respectively. In chronic studies, rats were fed nutritionally complete liquid diets containing either ethanol or glucose (controls) for up to 6 weeks. In acute studies, rats were given single boluses of ethanol and rates of protein synthesis were examined at 2.5 h. The results show that the myopathy is due to defective skeletal muscle protein synthesis. The information gained from these studies enhances our understanding of skeletal muscle diseases characterized by preferential effects on anaerobic fibres and should be applicable to disease processes in other toxic or metabolic myopathies.