The demonstration of protein-bound 99Mo-di- and trithiomolybdate in sheep plasma after the infusion of 99M0-labelled molybdate into the rumen.
1. Protein-bound, trichloracetic acid- (TCA) insoluble 99Mo appeared in plasma a few hours after the introduction of 99Mo-labelled molybdate (30 mg Mo) into the rumen of sheep maintained on a basic diet supplemented with elemental sulphur (3 g S/d). 2. Most of the 99Mo could be displaced from its protein carrier in vitro and the labelled compounds displaced were identified by sephadex G-25 chromatography as di- and trithiomolybdate. Tetrathiomolybdate was not detected. 3. In control experiments protein-bound, TCA-insoluble 99Mo predominated in plasma after the direct administration of [99Mo]tetrathiomolybdate, either into the rumen or intravenously. The 99Mo could be displaced in vitro and [99Mo]tetrathiomolybdate identified, although [99Mo]trithiomolybdate was also present. The study provides direct evidence of thiomolybdate synthesis and absorption in ruminants in vivo.
D000818:Animals; D002850:Chromatography, Gel; D007408:Intestinal Absorption; D008297:Male; D008982:Molybdenum / Q000097:blood* / Q000378:metabolism*; D011485:Protein Binding; D011868:Radioisotopes; D012417:Rumen / Q000378:metabolism*; D012756:Sheep; D013997:Time Factors
D011868:Radioisotopes; C034539:dithiomolybdic acid; C034540:trithiomolybdic acid; D008982:Molybdenum; C020809:tetrathiomolybdate