Thyroidal I131 collection in normal and adrenalectomized rats, effect of desoxycorticosterone acetate and physiological saline.

Abstract

SummaryAdrenalectomized male rats, fed an iodine deficient diet and maintained on 1/4/ mg DCA daily, were injected intravenously with I131 containing 8.5 μg of iodide carrier. Thyroidal collection of I131 increased at 3 hr after 1.25 mg DCA 100 g. but not at 1 1/2 hr after 1 1/2 mg DCA 100 g, the DCA being given intraperitoneally immediately after I131 in both groups. There was no change from controls in plasma I131 level or urinary I131 excretion. Under similar conditions, adrenalectomized rats showed increased thyroidal I131 collection 3 hr and 1 1/2 hr after intraperitoneal injection of 10 ml 0.9% NaCl/100 g. This occurred despite decreased plasma radioactivity and increased urinary I131 excretion. Intact rats studied under the same conditions showed no change from controls in thyroidal I131 collection, but had less radioactivity in their blood plasma.