EFFECT OF TESTOSTERONE PROPIONATE ON THE DISTRIBUTION OF RADIOACTIVE IODIDE IN RECENTLY THYROIDECTOMIZED RATS

Abstract

Distribution of intravenously administered ¹³¹Iodide (¹³¹I) was studied in spayed rats which had been thyroidectomized on the previous day. Pretreatment with testosterone propionate (2 mg daily for 8 days) resulted in decreased ¹³¹I blood levels both in non-nephrectomized and nephrectomized animals. In the latter, no loss of radioactivity from the body occurred within the time limits of the experiments (up to 10 hours after ¹³¹I administration). In most organs, ¹³¹I concentrations were lowered after testosterone pretreatment, but in the skin a markedly increased uptake was found. To a minor extent, enhanced concentration of ¹³¹I was present in an extrahepatic abdominal storage site.