Takarmányok D-triptofántartalmának felszívódása és felhalmozódásapatkányok belső szerveiben

Abstract

SUMMARY Background: Because of the difficulty in determining D-tryptophan, the total content of D-tryptophan in the internal organs of the rats was not studied before. A new protein hydrolysis method, free of racemization, allowed us to measure the absorption and accumulation of D-tryptophan in the rat’s internal organs.Objectives: After the appropriate analytical method was available, different amounts of D-Trp were fed to rats and tested for its absorption and accumulation in certain (spleen, liver, kidney) organs of the animals.Materials and methods: We applied one-time and continuous D-Trp dosing in 200 and 400, and 100, 200, 350 and 600 mg/bwkg, respectively, where the D-amino acid was mixed into the feeding stuff. After the feeding period (three weeks) was over, samples were taken from the kidney, liver, and spleen, and the total D-Trp content were measured. Results and discussion: Following a one-time D-Trp input, D-Trp cannot be detected in the organs, like in the case of the control animals. The weight gain of the animals was the same as for the control animals, which is supported by the fact, that rats can utilize D-Trp the same effectiveness as the L-enantiomer. For the kidney from the 100, for the liver from the 200 mg/bwkg dosage made the organs’ D-Trp content measurable. In case of every treatment the ratio of D-Trp is the highest in the spleen, and by increasing the dosage, the differ-ence between the D-Trp% measured in the spleen and the other two organs is increasing. In case of kidney, D-Trp can be detected for lower doses, for the three highest doses we cannot differentiate between the organs and the doses.The accumulation least affected the liver, because the D-amino acid oxidase system is taking place there. Kidney was a bit more sensitive for the presence of D-Trp, because the studied amino acid can be detected in case of smaller doses. For higher doses kidney did not show a remarkable difference from liver, and the highest accumulation could be found in the spleen, because in this organ there is no special procedure taking place for the removal of D-amino acids.