The effect of protein malnutrition on the capacity for protein synthesis during wound healing.

Abstract

It has been shown that wound healing in the rat is associated with increased protein synthesis at the site of the wound 48 hours after surgical trauma. The aim of the current study was to examine the effect of protein malnutrition prior to abdominal surgery on the capacity for muscle protein synthesis both at the site of the wound and in undamaged abdominal muscle. Thirty-two rats were randomly assigned to a low or high protein diet (3% and 20% casein respectively). After two weeks, half the rats in each group underwent abdominal surgery. Forty-eight hours after the operation all the animals were killed and tissues were analysed for RNA and protein contents. The capacity for protein synthesis, as indicated by the RNA:protein ratio, was increased at the site of the healing wound. The low protein diet caused a decrease in the capacity for protein synthesis in unoperated animals but did not prevent the increase associated with wound healing. The capacity to increase protein synthesis during wound healing is protected against the effects of malnutrition, indicating that it has a high biological priority.