Thyroidal I 131 Collection in Normal and Adrenalectomized Rats,Effect of Desoxycorticosterone Acetate and Physiological Saline. ∗

Abstract

Summary

Adrenalectomized 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.