The effect of surgical trauma and insulin on whole-body protein turnover in parenterally-fed undernourished patients.
Ten undernourished patients receiving total parenteral nutrition and undergoing major intestinal surgery were restarted on intravenous feeds identical to their pre-operative regimens within 24 h of their operation. Five, chosen at random, received post-operatively 1-2 units insulin/kg body weight/24 h with their feed, while the other five received the feed only. Pre-operatively, and 2 h after commencing their post-operative feeds, rates of whole-body protein synthesis and breakdown were measured over a 9-h period following intravenous injection of a single tracer dose of 15N-glycine by the ammonia and urea end-product methods. During these 9-h study periods measurements were also made of blood glucose, plasma insulin and glucagon, urinary ammonia, nitrogen, creatinine and 3-methylhistidine. Blood glucose and plasma insulin and glucagon concentrations rose post-operatively whether or not insulin was given, but the increment in insulin concentration was significantly greater when insulin was given. Apparent nitrogen balance was positive pre-operatively and became less so post-operatively whether insulin was given or not. Similarly, post-operative increments in urinary excretion of ammonia, creatinine and 3-methylhistidine were not altered by addition of insulin. Protein turnover, as estimated by the ammonia end-product method, tended to rise post-operatively, but there was no significant difference between the increases observed with or without insulin. The urea end-product method suggested that there was no change in whole-body protein turnover after surgery, whether or not insulin was given. This study does not support the clinical use of insulin as a means of modifying protein metabolic losses after major surgery.
D000293:Adolescent; D000328:Adult; D000368:Aged; D000641:Ammonia / Q000652:urine; D001786:Blood Glucose / Q000378:metabolism; D003404:Creatinine / Q000652:urine; D005260:Female; D005934:Glucagon / Q000097:blood; D006801:Humans; D007328:Insulin / Q000008:administration & dosage* / Q000097:blood; D007422:Intestines / Q000601:surgery; D008297:Male; D008762:Methylhistidines / Q000652:urine; D008875:Middle Aged; D009584:Nitrogen / Q000652:urine; D009748:Nutrition Disorders / Q000378:metabolism*; D010288:Parenteral Nutrition; D011506:Proteins / Q000378:metabolism*; D013514:Surgical Procedures, Operative; D014508:Urea / Q000378:metabolism
D001786:Blood Glucose; D007328:Insulin; D008762:Methylhistidines; D011506:Proteins; D000641:Ammonia; D014508:Urea; D005934:Glucagon; D003404:Creatinine; C028118:3-methylhistidine; D009584:Nitrogen