Kinetics and metabolic effects of orally administered ornithine alpha-ketoglutarate in healthy subjects fed with a standardized regimen

Abstract

In accordance with previous results obtained with traumatized patients, ornithine alpha-ketoglutarate (OKG) was orally administered to 10 healthy subjects fed with a standardized regimen. Six similarly fed control subjects received only water. Plasma and 24-h urinary amino acids and alpha-ketoglutarate, plasma glucose, plasma insulin, and urine urea were all measured. After administration of ornithine alpha-ketoglutarate, the rapid decrease in blood ornithine to basal values, the absence of any increase in plasma alpha-ketoglutarate levels, and the minimal increase in ornithine, alpha-ketoglutarate, and urea urinary elimination, all indicated intense metabolism and utilization of the two compounds. These results suggest that the hyperornithinemia observed in 4-h fasting, traumatized patients receiving ornithine alpha-ketoglutarate reflects a metabolic perturbation in the utilization of this amino acid after trauma, rather than a hypothetical slow utilization. On the other hand, ornithine alpha-ketoglutarate induced an increase in insulin levels causing hypoglycemia and probably a decrease in plasma levels of several amino acids.