[Protein turnover and amino acids metabolism in septic rats]

This study was carried out to elucidate the protein and amino acids metabolism in septic rats, using constant infusion of 1-13C-leucine (4mg/hr), 5-13C-glutamine (2mg/hr), 1,2-13C-leucine (4mg/hr), or U-14C-leucine (2.0uCui/hr). Whole body protein kinetics showed that protein breakdown rate was increased in sepsis, but no change was found on protein synthesis rate (PSR). Intestinal mucosal fractional synthesis rate (FSR) was increased with sepsis. However, sepsis caused significant decrease of muscle FSR. Both leucine and glutamine oxidation rates were significantly increased in sepsis. Fraction of leucine degradation via glutamine was significantly increased in sepsis. We concluded that 1) both leucine and glutamine were utilized as important energy fuels in sepsis, 2) whole body PSR was influenced by the change of PSR in each organ, 3) the pathway from leucine to glutamine was significant in the degradation of leucine.