Skeletal muscle atrophy is a common feature in alcoholism and affects up to two thirds of alcohol misusers and women appear to be particularly susceptible. There is also some evidence to suggest that malnutrition exacerbates the effects of alcohol on muscle. However, the mechanisms responsible for the myopathy remain elusive and some studies suggest that acetaldehyde rather than alcohol is the principal pathogenic perturbant. Previous reports on rats dosed acutely with ethanol (<24h) have suggested that increased proto-oncogene expression (i.e., c-myc) may be a causative process, possibly via activating pre-apoptotic or transcriptional pathways. We hypothesised that (A) increases in c-myc mRNA levels also occur in muscle exposed chronically to alcohol, (B) muscle of female rats are more sensitive than those from male rats, (C) raising acetaldehyde will also increase c-myc, (D) prior starvation will cause further increases in c-myc mRNA expression in response to ethanol and (E) other genes involved in apoptosis (i.e., p53 and Bcl-2) would also be affected by alcohol. To test this, we measured c-myc mRNA levels in skeletal muscle of rats dosed either chronically (6-7 weeks; ethanol as 35% of total dietary energy) or acutely (2.5 hours; ethanol as 75 mmol/kg body weight, i.p.) with ethanol. All experiments were carried out in male Wistar rats (approx. 0.1-0.15 kg body weight) except study (II) which examined gender susceptibility in male and female rats. At the end of the studies, rats were killed and c-myc, p53 and Bcl-2 mRNA was analysed in skeletal muscle by reverse transcription-polymerase chain reaction (RT-PCR) with an endogenous internal standard, GAPDH. The results showed that (A) in male rats fed ethanol chronically, there were no increases in c-myc mRNA: (B) increases however occurred in c-myc mRNA in muscle from female rats fed ethanol chronically: (C) raising endogenous acetaldehyde with cyanamide increased c-myc mRNA in acute studies: (D) starvation per se increased c-myc mRNA levels and at 1 day potentiated the acute effects of ethanol, indicatative of a sensitisation response: (E) the only effect seen with p53 mRNA levels was a decrease in muscle of rats starved for 1 day compared to fed rats and there was no statistically significant effect on Bcl-2 mRNA in any of the experimental conditions. The increases in c-myc may well represent a pre-apoptotic effect or even a non-specific cellular stress response to alcohol and/or acetaldehyde. These data are important in our understanding of a common muscle pathology induced by alcohol.