EFFECT OF SURGICAL TRAUMA ON MUSCLE PROTEIN-SYNTHESIS IN THE RAT

The rate of protein synthesis in skeletal muscle was measured in vivo in rats at various times during the first 2 days after abdominal surge ry. Protein synthesis in abdominal muscle at the site of the wound was slightly reduced 2 h after operation, had returned to normal by 24 h and was massively increased by 48 h after surgery. In contrast, there was no change at any time in the rate of protein synthesis in either t he gastrocnemius muscle or abdominal muscle distant from the wound sit e. Surgery had no effect on the weight or protein content of the gastr ocnemius muscle, although urinary nitrogen excretion was increased rel ative to food intake, indicating the presence of a net catabolic respo nse. Changes in whole-body protein turnover in response to uncomplicat ed abdominal surgery are thus likely to reflect the anabolic processes of wound healing and repair as well as any catabolic response in unin jured tissues.