UPTAKE, TURNOVER AND EXCRETION OF 1-131 BY RAINBOW TROUT (SALMO GAIRDNERI)

Abstract

1. NaSCN inhibits I-131 uptake by the lower jaw (thyroid) and increases the rate of loss of I-131 from trout, presumably by way of the gills. 2. The biological half-life (T ½) of ionic I-131 in the blood plasma of trout is 1.7 days. 3. I-131 is excreted in the urine and by the gills, with the urinary loss being 3.8 times that of the gill per unit time. 4. The I-131 urine/ plasma ratios indicate that the trout kidney absorbs much of the filtered iodide.