Abstract
Male fetal rats were castrated in utero on the 21st day of gestation. Twenty-four hrs after the operation, they were given a subcutaneous injection of 22.5μCi of 3H-leucine. One hr later they were autopsied, and their pituitaries were examined autoradiographica lly by the dipping method. Our experiment showed a significant increase in both leucine uptake and percentage of basophilic cells after the castration. Since the parallel relationship between the uptake of leucine and the biosynthesis of anterior pituitary hormones have been recently elucidated, the significant enhancement of leucine uptake by basophilic cells suggests the increase in production of gonadotrophic hormones by these cells. The increase in percentage of basophilic cells also supports the view of the existence of feedback mechanism between the testis and the hypothalamic-pituitary axis in the fetal rat.
