UREA AND PROTEIN-METABOLISM IN BURNED CHILDREN - EFFECT OF DIETARY-PROTEIN INTAKE

The response of urea metabolic kinetics, the rate of whole-body protei n breakdown, and muscle and skin protein synthesis rates to dietary pr otein intake (1.15 to 2.92 g/kg/d) was assessed in children with 20% t o 40% total body surface area burn injury using a primed continuous in fusion of N-15(2)-urea and L-C-13(6)-phenylalanine. Plasma urea concen tration, production, and excretion rates increased with dietary protei n intake without evidence of approaching maximum plateau values, There was no consistent evidence of urea recycling in these subjects (urea production=excretion) at any level of protein intake. The rate of appe arance (Ra) of phenylalanine (an index of whole-body protein breakdown ) and rate of muscle protein synthesis were independent of dietary pro tein, whereas there was a significant increase in skin protein synthes is with higher protein intake. We conclude that there seems to be litt le benefit of high protein intake on whole-body protein breakdown and muscle protein synthesis rates in these burn patients, although high-p rotein diets may enhance wound healing. Copyright (C) 1997 by W.B. Sau nders Company.