Dietary Composition and Tissue Protein Synthesis I. Effect of Tryptophan Deficiency.

Rate of collagen synthesis, as measured by 1-C14-glycine uptake, by skin and in subcutaneously implanted polyvinyl sponge has been shown to vary with age and diet. A tryptophan-deficient diet significantly reduced the rate of skin collagen synthesis in young animals. However, the greater loss of more labile components of the skin resulted in a relative greater percentage of skin collagen in this group. Rate of synthesis in the sponge was not significantly affected. The deficient animals showed an increased specific activity in liver and serum proteins, suggesting that protein synthesis probably occurs at a faster rate in the liver simultaneously with increased catabolism or utilization.