Effect of dietary manipulation on c-myc RNA expression in adipose tissue, muscle and liver of broiler chickens.

The effects of dietary restriction on the relative steady state levels of cellular myc (c-myc) mRNA in abdominal adipose tissue, breast muscle and liver of chickens were determined. Fasting was found to increase c-myc RNA expression in adipose tissue (p less than 0.01). This increase returned to normal levels after refeeding. Muscle and liver in fasted birds did not show changes in c-myc that differed from controls. Serum concentrations of glucose, triglyceride (TG), free fatty acids (FFA) and insulin-like growth factor (IGF-I) were compared to levels of c-myc found in control birds. In adipose tissue, c-myc levels were negatively correlated with serum glucose, TG and IGF-I, while in muscle a positive correlation with serum glucose and TG was found. Data suggest that c-myc is involved in the metabolic changes occurring in fat cells under fasting conditions.