Use of an intravenous branched chain amino acid enriched diet in the tumor-bearing rat.

The purpose of this study was to determine whether a branched chain amino acids (BCAA) enriched intravenous feeding would have an effect on nitrogen retention in the host tissue, without stimulating tumor growth in the malignant tumor bearing animal. NEDH/c rats with an implanted fibrosarcoma were put on one of two total parenteral nutrition regimens, one of an amino acid formula containing 25 per cent BCAA, by weight and the other containing 50 per cent BCAA. Nitrogen retention in the two tumor-bearing groups was similar, although it was 47 per cent greater than observed in the non-tumor bearing animals (p less than 0.05). Skeletal protein synthesis was significantly reduced by the presence of the tumor in rats on the 25 per cent BCAA formula (from 10.1 per cent/day to 6.1 per cent/day) but was increased to 7.9 per cent/day by the 50 per cent BCAA formula. The BCAA enriched intravenous feeding does not enhance tumor growth and supports skeletal protein synthesis, at least in this experimental model.