The N-glycine constant infusion method was used to study protein turnover in normal adults and perioperative patients.The protein turnover rate （Q）

synthetic rate （S） and catabolic rate （C） were derived according to Picou’s two-pool system model

and the“end-product averaging technique”showed the

15

N-glycine constant iufusion method to be reliable

with a reproducibility of ±5.1%.This measurement can be repeated after a short period

so it should be useful for surgical nutrition study. Our results show the following:Q was significantly increased after operation （3.4± 0.6 to 5.0±0.5 g protein/kg/d

P

<

0.01）

and S （2.6±0.5 to 3.7±0.6 g protein/kg/d

P

<

0.05） and C （2.3±0.5 to 3.9±0.5 g protein/kg/d

P

<

0.01） were increased as well.This suggests that the protein degradation rate outstripped the synthesis rate on post-operative day three （POD+3） when traditional （glutamine-free） total parenteral nutrition support was used.