Failure of additional ketoanalogues of branched chain amino acids to improve the response to parenteral nutrition after experimental trauma in the rat

Abstract

The ketoanalogues of branched chain amino acids (KAA) may improve the post-traumatic protein metabolism. We studied the effects of additional KAA, supplied as a part of total parenteral nutrition (TPN), on liver protein synthesis and nitrogen balance in rats after standard surgical trauma. A TPN-regimen, containing 36 mmol/kg/day KAA and 58 mmol/kg/day amino acids was compared to an isonitrogenous (1.0 gN/kg/day) TPN-regimen containing 58 mmol/kg/day amino acids and no KAA in a 48 h experiment. The liver protein synthesis measured by perfusion with C 14-leucine in vitro was similar in both groups 2 days after surgery (59.2 ± 16.2 vs. 64.3 ± 15.6 arbitrary units, mean ± SD). The nitrogen balances were negative and of similar magnitude (−0.66 ± 0.36 vs. −0.17 ± 0.45 gN/kg/48 h, mean ± SD). We conclude that TPN supplemented by high supply of KAA offers no systematic advantage over TPN alone after experimental surgical trauma.