Effect of oestradiol benzoate on pituitary and testis function in the normal adult male rat.

The effects of estradiol benzoate (EB) on: 1)levels of testosterone in serum and in testis tissue 2) pituitary and serum LH and FSH levels and 3) the weights of seminal vescicles ventral prostates and testes were studied in adult male rats. Daily subcutaneous administration of 1mcg or more EB significantly (p less than .05) lowered serum LH levels as compared to controls and levels of pituitary LH were suppressed after daily treatment with 100mcg EB. Serum and pituitary levels of FSH significantly (p less than .05) declined in rats given 10 or 100 mcg EB daily for 7 days. A dose of 1mcg or more per day for 7 days induced a significant (p less than .05) lowering of both serum and testis tissue testosterone. Doses of 10mcg or more EB daily for 7 days significantly (p less than .05) reduced testicular weight. Weights of seminal vescides and ventral prostates were decreased with daily administration of 1mcg or more EB.