The Effects of Testosterone Propionate and Estradiol Benzoate on the in vitro Synthesis of FSH

Abstract

The effect of testosterone propionate (TP) and estradiol benzoate (EB) on pituitary and plasma FSH and in vitro synthesis of FSH in pituitary tissue was investigated in adult male rats. A marked dichotomy in the effects of these two sex hormones was discovered. EB produced a drop in pituitary FSH content and concentration by the fourth day of treatment, and by the 28th day, the content dropped by 6 percent and concentration to 3 percent of pretreatment values. The synthesis showed a similar decline. Serum levels remained, however, unchanged for the first 14 days of the experiment and showed only a slight decline by the 21st and 28th days. TP induced a progressive increase in pituitary content and concentration of FSH, while serum levels remained unchanged for the first 7 days and later showed a slight drop. The synthesis studies failed to reveal a consistent pattern; however, in no instance was there noted a decrease in the incorporation of radiolabeled leucine into immunoprecipitable FSH. On the basis of these data, it is suggested that in normal adult male rats EB and TP have different effects on pituitary FSH.