Tissue Distribution and Excretion of Radioactivity following Administration of 14C-Labeled Deoxynivalenol to White Leghorn Hens. PRELUSKY, D.B., HAMILTON, R.M.G., TRENHOLM, H.L., AND MILLER, J.D. (1986). Fundam. Appl. Toxicol. 7, 635-645. The disposition of [14C]deoxynivalenol ([14C]DON) administered to hens as either a single oral dose or consumed in spiked feed over a 6-day period was determined by tracing the specific radioactivity of tissues and excreta. Following a single intubated dose (2.2 mg [14C]DON; 2.4 μCi/bird), the toxin was found to be poorly absorbed; peak plasma levels (2-2.5 hr post-treatment) accounted for less than 1% of the administered dose. Maximum tissue residues were measured at 3 hr in all tissues (liver, kidney, brain, heart, spleen, proventriculus, gizzard, small intestine) except for fat, muscle, and oviduct which occurred at 6 hr postdosing. Among the organs, the highest activities were measured in kidney, liver, and spleen; however, these levels were equal to less than 500 ng DON equivalents/g tissue, and declined quickly. Clearance of radioactivity from tissue had an average half-life of 16.83±8.2 hr (range 7.7-33.3 hr, depending on the tissue). Elimination of the labeled toxin in excreta occurred rapidly; recovery of radioactivity accounted for 78.6,92.1, and 98.5% of the dose by 24,48, and 72 hr, respectively. In continuously dosed birds fed 2.2 mg unlabeled DON for 6 days followed by 2.2 mg (1.5 μCi) [14C]DON for 6 days, accumulation of radioactivity in tissues did not occur. Maximum residual levels, which occurred in the kidneys, were only 60 ng DON equivalents/g. Estimated level of residues contained in the edible tissues amounted to only 13-16 μg DON/1.5 kg hen.