Ornithine α-Ketoglutarate and Glutamine Supplementation During Refeeding of Food-Deprived Rats

The aim of this study was to compare the efficiency of ornithine α-ketoglutarate (OKG) and glutamine supplementation in an experimental model of denutrition that provides well-characterized disturbances of amino acid patterns. Male Wistar rats (187 ± 11 g; five in each group) were starved for 3 days and then refed for 7 days with an oral diet (192 kcal kg-1 · day -1 and 2.25 g of nitrogen kg-1 · day-1), supplemented with 0.19 g of nitrogen kg-1 · day-1 in the form of OKG, glutamine, or casein (control group). Food deprivation induced a fall in most tissue amino acids, with the notable exception of muscle leucine and liver glutamate, which increased by 43% (p < .01), and 11% (p < .05), respectively. The main effect of OKG was seen in the viscera, with a normalization of most amino acid pools (including proline and branched-chain amino acids) in the small bowel and liver. The main effect of glutamine was observed in the muscle, with a normalization of the glutamine and leucine pools. We conclude that, in this model and with the doses used, OKG and glutamine act in different target tissues, ie, splanchnic areas and muscle, respectively. (Journal of Parenteral and Enteral Nutrition 16:505-510, 1992)