Simultaneous infusion of glutamine and branched-chain amino acids (BCAA) to septic rats does not have more favorable effect on protein synthesis in muscle, liver, and small intestine than separate infusions.
BACKGROUND
Glutamine and branched-chain amino acids (BCAA; valine, leucine, and isoleucine) are used as nutrition supplements in the treatment of proteocatabolic illness. We hypothesized that simultaneous administration of BCAA and glutamine affects protein metabolism more significantly than separate administration. In the present study, we evaluated their effect on protein synthesis in skeletal muscle, liver, and jejunum of septic rats.


METHODS
Twenty-four hours after induction of sepsis by subcutaneous injection of turpentine, the rats were infused for 6 hours with 5 mL of 1.75% glutamine, 1.75% BCAA, 1.75% glutamine+BCAA, or saline solution. The control group consisted of intact rats infused with saline. Protein synthesis was measured at the end of infusion by a "flooding method" with [3,4,5-(3)H]phenylalanine.


RESULTS
In turpentine-treated animals, we observed a decrease in glutamine concentration in blood plasma and skeletal muscle, a decrease in BCAA concentration in liver and jejunum, and a decrease in protein synthesis in all tissues. Glutamine or glutamine+BCAA infusion increased glutamine concentration in plasma and muscle and stimulated protein synthesis in the liver. The BCAA infusion enhanced concentrations of BCAA in plasma and tissues, but the effect of BCAA on protein synthesis was insignificant. Synergistic effect of simultaneous infusion of glutamine and BCAA on protein synthesis was not observed.


CONCLUSIONS
We conclude that glutamine infusion to rats with septic injury may significantly improve impaired protein synthesis in the liver and that there is no synergistic effect of glutamine and BCAA infusion on protein synthesis in skeletal muscle, liver, and jejunum.
Holecek
Milan
M
Department of Physiology, Charles University, Medical Faculty, Hradec Kralove, Czech Republic. holecek@lfhk.cuni.cz
Muthny
Tomas
T
Kovarik
Miroslav
M
Sispera
Ludek
L
D000597:Amino Acids, Branched-Chain / Q000008:administration & dosage / Q000378:metabolism*; D000818:Animals; D004359:Drug Therapy, Combination; D005973:Glutamine / Q000008:administration & dosage / Q000378:metabolism*; D007263:Infusions, Parenteral; D007421:Intestine, Small / Q000187:drug effects / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism; D014176:Protein Biosynthesis / Q000187:drug effects*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D018805:Sepsis / Q000628:therapy*; D016896:Treatment Outcome
D000597:Amino Acids, Branched-Chain; D005973:Glutamine