EFFECT OF DIETARY RESTRICTION ON PROTEIN-SYNTHESIS AND WOUND-HEALING AFTER SURGERY IN THE RAT

1. The healing of an abdominal muscle wound after surgery is associate d with a considerable increase in the rate of protein synthesis, We ha ve investigated whether this increase in protein synthesis is affected by chronic undernutrition, and whether this causes a delay in wound h ealing, 2, A group of rats was fed 58% of the voluntary food intake of a matched control group, After 7 days half the rats in each group und erwent abdominal surgery, Forty-eight hours later all the rats were ki lled and muscle protein synthesis rate was measured by the flooding do se technique, 3, In a second experiment using the same dietary regimen rats were placed in metabolic cages after surgery and killed 7 days l ater, In addition to measurements of muscle protein synthesis, wound b reaking strength was measured with a tensiometer and collagen content was also measured at the wound site, 4, Dietary restriction caused a l oss of body weight, a decrease in nitrogen balance and a deficit in mu scle protein mass, It also caused a decrease in protein synthesis rate in gastrocnemius muscle and in parts of the abdominal muscle distant from the site of the wound, However, it had no effect on the rate of m uscle protein synthesis at the site of the wound either 2 or 7 days af ter surgery, The tensile strength and the collagen content of the woun d were also unaffected by food restriction, 5, It is concluded that th e wound healing process is uniquely protected from the effects of mode rate undernutrition such as might be experienced by a chronically ill patient.