新生児及び乳児における術後蛋白代謝の研究 : 尿中 3-methylhistidine 排泄量を中心に

抄録

Urinary excretion of 3MH, NPN, and creatinine was measured in 48 pediatric surgical patients for the first 8 days after the operation. The normal values of 3MH excreted in the urine were; 0.409±0.051mg/kg/day in 2 days old newborns (n=10, M±SD), 0.483±0.065mg/kg/day in 7 days to 1 month old infants (n=30), 0.472±0.059mg/kg/day in 1 month to 6 months old infants (n=15), and 0.463±0.049mg/kg/day in 6 months to 1 year old infants (n=12). Urinary excretion of 3MH was significantly low in 2 days old newborns, when compared with those in the other age groups. Marked increase of urinary excretion of 3MH an NPN was observed shortly after the operation and the amount of 3MH and NPN excreted in the urine gradually decreased thereafter. After the fifth postoperative day, no significance was found between pre- and postoperative urinary excretion of 3MH and NPN. Urinary excretion of 3MH and NPN seems to be dependent upon the extent of surgical invation. There was a close correlation between the duration of operation and urinary excretion of both 3MH and NPN on the first two postoperative days. Urinary excretion of 3MH and NPN increased in whom intake of calories was below 50 Cal/kg/day or the nitrogen balance was negative. Increase of urinary excretion of 3MH and NPN after the operation was more significant in neonates within 6 days after birth than in infants of the other age groups. It was suggested that the urinary excretion of 3MH is dependent upon the degree of muscle damage. There was a close correlation between 3MH/Cr and 3MH excretion. The results of the present studies disclosed that the urinary excretion of 3MH and NPN is a useful indicator for evaluation of the postoperative protein metabolism.