Contribution of skeletal muscle protein in elevated rates of whole body protein catabolism in trauma patients.
Whole body protein breakdown using 15N and skeletal muscle protein breakdown from urinary 3-methylhistidine were measured simultaneously in seven skeletal trauma and eight normal subjects on a standard hypocaloric, protein free diet. The trauma group had a 31% greater resting metabolic energy expenditure than controls. The control males lost 3.73 mumol/kg/day of 3-methylhistidine which suggested a protein breakdown rate of 0.89 g P/kg/day. The control females lost 2.46 mumol/kg/day of 3-methylhistidine or a breakdown rate of 0.58 g P/kg/day. These parameters were 187% greater for males and 163% greater for females in the trauma group. The measured whole body protein breakdown rates were 3.64 g P/kg/day for the control males and 2.69 for females. Skeletal trauma increased both by 73%. Skeletal trauma raised the muscle contribution to the whole body breakdown rate from 24.4 to 40.4% for men and from 21.6 to 33.0% for women. This disproportionate increase in muscle protein breakdown is consistent with muscle protein metabolism being most seriously affected by severe injury.
D000328:Adult; D000409:Alanine / Q000378:metabolism; D003404:Creatinine / Q000652:urine; D004044:Dietary Proteins / Q000008:administration & dosage; D004734:Energy Metabolism; D005260:Female; D050723:Fractures, Bone / Q000378:metabolism*; D006639:Histidine / Q000031:analogs & derivatives*; D006801:Humans; D008297:Male; D008762:Methylhistidines / Q000652:urine*; D008875:Middle Aged; D009124:Muscle Proteins / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D012737:Sex Factors
D004044:Dietary Proteins; D008762:Methylhistidines; D009124:Muscle Proteins; D011506:Proteins; D006639:Histidine; D003404:Creatinine; C028118:3-methylhistidine; D000409:Alanine