Protein-sparing effect of intravenously administered branched chain amino acids in adult rats.
Branched chain amino acids (BCAA) serve as intermediate energy substrates for peripheral tissues. Experiments were conducted to evaluate protein-sparing properties of BCAA at different doses without dextrose. Forty healthy male adult Wistar rats, weighing 437 +/- 34 gm, were randomly assigned to one of five groups. Four groups of eight rats were cannulated at the jugular vein and infused with 3% amino acid solutions containing 13, 23, 50 or 100% BCAA; an additional eight fasted rats served as controls. Results show that weight loss was not significantly different between groups, but was lower than in the fasted rats. Nitrogen balance (NB) was least negative in the 23% BCAA group, followed by 13, 50 and 100% BCAA. Protein-sparing index (PSI), defined as that portion of the infused nitrogen that is used for sparing body proteins, agreed with the calculated fat/protein ratios. Higher PSI and fat/protein ratios resulted from solutions containing balanced amino acid patterns (13 and 23%). No obvious imbalances in plasma amino acid patterns were observed. It is concluded that more protein conservation can be achieved with amino acid solutions containing a balanced amino acid pattern and that the effect of additional BCAA on protein conservation is limited in adult rats.
D000596:Amino Acids / Q000097:blood; D000597:Amino Acids, Branched-Chain / Q000008:administration & dosage* / Q000097:blood; D000818:Animals; D004044:Dietary Proteins / Q000008:administration & dosage*; D008297:Male; D009584:Nitrogen / Q000378:metabolism; D051381:Rats; D013217:Starvation
D000596:Amino Acids; D000597:Amino Acids, Branched-Chain; D004044:Dietary Proteins; D009584:Nitrogen