Variations tions in Iodine 131 uptake by some organs of white rats and its changes during the estrous cycle

Abstract

It has been studied the Iodine¹³¹ uptake by some organs of Wistar white rats (12 males and 20 females), with average weight of 325 g and nearly 5 months old. Females were divided into groups according to the phase of estrous 9 cycle, which was detected by vaginal smears. Iodine¹³¹ was administered subcutaneously in a concentration ratio of 0.10 µ Ci by g/weight. The organs (thyroid, liver, kidney, spleen and pancreas) were withdrawn one hour later and Iodine¹³¹ uptake was detected by a Tobor Large Sample Couting Systems with Nal crystal. Absorption of Iodine¹³¹ was the largest by the thyroid, decreasing it in the estrous rats. There was no sexual difference, saved, the estrous cycle rats. It is discussed the 12 relationship between the thyroid gland and sexual hormones.