Abstract
The weight of the ventral prostate of hypophysectomized immature male rats was used to assay for serum ICSH content. Small amounts of ICSH were detected in the intact adult male and female rats, and larger amounts were detected in the serum of gonadectomized rats. Castrated males had a significantly greater serum ICSH content than spayed females. Both estrogen and androgen reduced the level of ICSH in the castrate male, but only estrogen was effective in the spayed female.