[Effects of supplementation with branched-chain amino acids on protein-nutritional status in rats treated by carbon tetrachloride].

A study was conducted to investigate effects of oral supplementation with branched-chain amino acids (BCAA) on protein-nutritional status in rats with liver cirrhosis. Liver cirrhosis was induced in male strain Sprague-Dawley rats by simultaneously administrating carbon tetrachloride (500 mg/kg, twice a week, intracutaneously) and phenobarbital (0.05% in drinking water, ad libitum) for 30 weeks. Following treatment with carbon tetrachloride and phenobarbital, cirrhotic rats received oral supplementation of BCAA with varying ratio among isoleucine (Ile), leucine (Leu) and valine (Val), or with varying content of total BCAA in the diet (Final content of total nitrogen was kept consistent by addition of glutamine). Nutritional efficacies of diets as described above were evaluated employing those protein-nutritional parameters as nitrogen balance and plasma levels of total protein, albumin and free neutral amino acids. Following results were obtained: 1. Compositional ratio of Ile:Leu:Val at 1:2:1.2 or at 2:1:1 was found to be more effective on diets which contained ILe:Leu:Val at 1:1:2 or either Val, Ile or Leu alone. 2. As to content of total BCAA in the diet (0, 2.5, 5, 10%), supplementation level of 2.5% was found to be most appropriate in terms of effects on nitrogen balance and on plasma protein concentration. In conclusion, 2.5% BCAA in the diet with the ratio of Ile:Leu:Val at 1:2:1.2 or 2:1:1 seems to be recommended to improve the impaired protein-nutritional status in liver cirrhosis.