Leucine and glutamine metabolism in septic rats.
The rate of leucine C-2 incorporation into glutamine was compared in control and septic rats. Female Sprague-Dawley rats (n = 46, 210-260 g) were fed parenterally for 3 days and then randomized into two groups (control and septic). Sepsis was induced by the injection of 10(10) live Escherichia coli/kg on day 4 into the septic group. Rats in each group were given a continuous (8 h) infusion of one of three different isotopes. The isotopes were given 24 h after inoculation. Leucine oxidation and incorporation into protein were determined with [1-13C]leucine; glutamine flux and oxidation were determined with [5-13C]glutamine, and the fraction of leucine C-2 incorporated into glutamine was determined by giving [1,2-13C]leucine. Results were as follows: sepsis caused a significant increase in the rate of leucine C-2 incorporation into glutamine (66.0 +/- 3.7 as against 29.6 +/- 3.7 mumol/h per kg, P less than 0.01). This increase was due to both an increase in glutamine production (2331 +/- 76 as against 1959 +/- 94 mumol/h per kg, P less than 0.01) and an increase in the proportion of glutamine derived from leucine (2.83 +/- 0.27% as against 1.51 +/- 0.31%, P less than 0.01). The ratio of leucine C-2 incorporated into glutamine to leucine oxidized increased from 7.16 +/- 0.91% to 11.49 +/- 1.12% with sepsis (P less than 0.05).
Yoshida
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Department of Surgery, University of Medicine and Dentistry of New Jersey, School of Osteopathic Medicine, Camden 08103.
Lanza-Jacoby
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Stein
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TP
D000818:Animals; D002247:Carbon Isotopes; D004927:Escherichia coli Infections / Q000378:metabolism*; D005260:Female; D005973:Glutamine / Q000378:metabolism*; D007700:Kinetics; D007930:Leucine / Q000378:metabolism*; D008433:Mathematics; D008954:Models, Biological; D010289:Parenteral Nutrition, Total; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D018805:Sepsis / Q000378:metabolism*
D002247:Carbon Isotopes; D005973:Glutamine; D007930:Leucine