title: [Determination of endogenous nitrogen in feces using the isotope technic].
abstract: A ration consisting of wheat gluten and N-free components was supplemented with L-lysine and L-leucine and fed to two groups of growing Wistar rats. Group 1 received 15N Lys and unlabelled Leu, group 2 received unlabelled Lys and 15N Leu in order to study the influence of the utilization of the 15N marker on the labelling quota of faeces and urine as well as various fractions of the body. The good utilization of Lys in group 1 results in a higher 15N excess in faeces and a reduced 15N abundance in urine in comparison to group 2 with a lower utilization of 15N Leu. The results show that the 15N abundance in urine is unsuitable as an indicator of the 15N labelling quota of endogenous metabolic faecal nitrogen.
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D005243:Feces / Q000032:analysis*; D007408:Intestinal Absorption; D008297:Male; D009584:Nitrogen / Q000032:analysis*; D009590:Nitrogen Radioisotopes; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D009590:Nitrogen Radioisotopes; D009584:Nitrogen
vernacular_title: Zur Bestimmung des endogenen Stickstoffs im Kot mit Hilfe der Isotopentechnik.