[Studies on the 14C-15N-acetamide turnover in sheep. 2. Studies on 15N turnover and comparative studies on the 14C turnover].
Three fistula sheep with average weights of 52.2 kgs were given 37.9 g of 15N and 14C labelled acetamide (= 1.09 mg 15N' and 0,95 mCi14C) which were administered directly through the fistula. The half-life period of 15N retention in the ruminal fluid (TCE soluble portion) was found to be 4 hrs. 18 hrs after 15N administration increasing amounts of 15N were carried back to the rumen by way of the rumino-hepatic circulation. The 15N concentration in the blood (TCE soluble portion) rapidly increased up to a peak value and, from 3 hrs after isotope administration, the 15N concentration was found to decline continuously, with a slight discontinuation at about the 10th hr of experiment. The rate of 15N incorporation into the protein fraction (TEC soluble portion) of the blood was delayed by 4 hrs, relative to the rate of 15N incorporation into ruminal proteins. An average of 43.1% of the administered amount of 15N was excreted in the urine within 7 days. Up to the 4th day of experiment the half-life period of urinary 15N excretion was 19 hrs. An average of 15% of the administered total amount of 15N was excreted in the faeces. In this process, the peak values in both TCE fractions were observed to occur on the 2nd day of experiment. The proportion of isotope in the TCE soluble fraction was found to increase continuously compared with the total amount of the isotope excreted in the faeces. Isotope concentrations between 0.03 and 0.13 atom% of surplus 15N were found in organ and muscle tissues of a sheep that had been slaughtered 7 days after administration of the isotope. The results obtained are discussed on the basis of comparisons made with the analogous behaviour of 14C activity.
D000081:Acetamides / Q000378:metabolism*; D000818:Animals; D002250:Carbon Radioisotopes / Q000378:metabolism; D009587:Nitrogen Isotopes / Q000378:metabolism; D012756:Sheep / Q000378:metabolism*
D000081:Acetamides; D002250:Carbon Radioisotopes; D009587:Nitrogen Isotopes
Untersuchungen zum Umsatz von 14C-15N-Azetamid bei Schafen 2. Mitteilung Untersuchungen zum 15N-Umsatz und vergleichende Betrachtungen zum 14C-Umsatz