Fractional rates of muscle protein synthesis and degradation in chickens with genetic muscular dystrophy.

Rates of synthesis (ks) and degradation (Kd) of muscle protein of normal (+/+) and muscular dystrophic (am/am) chicks of the GNS/2 strain obtained from a Fayoumi population were estimated based on the urinary excretion of N tau-methylhistidine. Both fractional rates of muscle protein synthesis and degradation of the line with muscular dystrophy at 4 and 20 weeks of age were greater than that of normal chicks. The muscular dystrophy gene affected the increase in rate of degradation more than the increase in fractional rate of synthesis.