[Biological availability of glutamine from N-acetyl-L-glutamine in intravenous administration. Studies in the rat].

Glutamine may be important especially in the catabolic patient, due to its universal role in transamination reactions. Because of its instability, until presently, glutamine is not included in amino acid solutions for parenteral nutrition. The availability of glutamine from the stable derivate N-acetyl-L-glutamine is investigated under the condition of a long-term parenteral nutrition by means of growth, N-balance, and amino acid concentrations in plasma, muscle and urine. For this purpose 2 groups of young healthy male rats (n = 6) are maintained entirely by parenteral nutrition for 12 days. Both groups are given 0.8 g N/kg/24 h as an amino acid solution without containing glutamine. Only one of the groups was supplied additionally with 0.4 g N as N-acetyl-L-glutamine. This resulted in a weight gain of 33 +/- 1.5 g and a cumulative N-balance of 1.5 +/- 0.045 g. In the group in which no acetyl-L-glutamine is given, weight gain is 27 +/- 1.8 g (p less than 0.05) and cumulative N-balance amounts only 1.16 +/- 0.034 g (p less than 0.001). In plasma and urine the amino acid concentrations are significantly elevated for the essential one in this group. The results indicate a good availability of glutamine from N-acetyl-L-glutamine when given intravenously to the rat.