Assessing effects of alcohol consumption on protein synthesis in striated muscles

The development of alcoholic muscle disease, which affects both cardiac and skeletal muscle, leads to increased morbidity and mortality in patients who abuse alcohol. The disease pathology includes myocyte degeneration, loss of striations, and myofilament dissolution, which is consistent with alterations in structural and myofibrillar proteins. One explanation for the changes in myofibrillar architecture is that the expression of cellular proteins may be compromised by ethanol consumption. The dynamic balance of proteins in striated muscle is dependent upon rates of protein synthesis and protein degradation. We have shown that protein synthesis is depressed in striated muscle after either acute alcohol intoxication or chronic alcohol ingestion. The loss of myofibrillar proteins occurs prior to any detection of abnormal muscle function in vivo. It is therefore of major importance to evaluate the regulation of protein turnover after ethanol consumption. This review describes protocols to study protein synthesis either in vivo or under in vitro conditions. The methods can be modified for studies involving transgenic mice allowing mechanisms responsible for the defects in protein synthesis to be dissected.