" CATABOLIC " LOSS OF BODY NITROGEN IN RESPONSE TO SURGERY

An infusion of 14C-leucine was used to measure the synthesis and breakdown rates of body protein before and after abdominal surgery. The postoperative loss of nitrogen was associated with a consistent fall in protein synthesis. The breakdown-rates also fell but to a smaller extent in three of four patients. These results suggest that the " catabolic" response to operative stress involves a fall in protein synthesis without an acute rise in breakdown-rates of body protein. © 1974.