[Absorption of 14C-leucine and 15N-leucine in rats after feeding a fish meal diet in comparison with a gelatin diet].
Albino rats received after nine days of adaptation to a fish meal diet in comparison with a gelatin diet 14C-U-Leucine and 15N-L-leucine via a pellet made from the specific diet after food deprivation for 15 h. Thereafter, the experimental animals consumed the non-labelled experimental diet ad libitum. Five times after the pellet intake, 30 min, and 1, 2, 4 and 6 h after injection of the labelled food, four experimental rats were sacrificed. The contents of the digestive tract and tissue samples were examined for 14C and 15N. We detected to following percentages of 14C-intake or the intake of 15N-excess (15N') in the TCA-soluble fraction of the gastric contents: [Formula: see text] We found in the TCA-soluble fraction of digesta of small intestine the following percentage of intake: [Formula see text] Where these values regarded as non-absorbed leucine, the 14C values obtained up to four hour period of experiment would be too high. Presumably, they are in the case of both diets simulated by other 14C-metabolites which originate from the leucine catabolism and reach the intestinal lumen. Amino acids labelled with 15N should be preferred in studies on the absorption of amino acids because, in case of catabolism, the 15N-aminogroup is excreted mainly in the form of urea via urine.
D000821:Animal Feed; D000818:Animals; D002250:Carbon Radioisotopes; D004044:Dietary Proteins; D005396:Fish Products; D005780:Gelatin; D007408:Intestinal Absorption; D007930:Leucine / Q000378:metabolism*; D008297:Male; D009587:Nitrogen Isotopes; D051381:Rats / Q000378:metabolism*
D002250:Carbon Radioisotopes; D004044:Dietary Proteins; D009587:Nitrogen Isotopes; D005780:Gelatin; D007930:Leucine
Untersuchungen zur Resorption von 14C-Leuzin und 15N-Leuzin nach Fütterung einer Fischmehldiät im Vergleich zu einer Gelatinediät an Versuchsratten.