Seminal vesicle and preputial gland response to steroids in adult male mice is influenced by prior intrauterine position.

There are differences in serum steroid concentrations during fetal life between male mice that develop between two male fetuses (2M males, with elevated testosterone) and between two female fetuses (0M males, with elevated estradiol). The present studies were undertaken to determine whether prior intrauterine position would influence the weight of seminal vesicles and preputial glands in adult male mice. To eliminate any potential differences between 2M and 0M males in circulating gonadal steroids, all males were castrated in adulthood and implanted with silastic capsules containing testosterone (T), dihydrotestosterone (DHT) or a combination of T and estradiol-17 beta (E2) or DHT and E2. Three weeks later, preputial glands were significantly heavier in 2M than 0M males after treatment with T but not DHT. Seminal vesicles were also significantly heavier (blotted wet weight) in 2M than 0M males after treatment with T. For 2M males, seminal vesicles weighed the same in response to treatment with T or DHT. However, relative to the effect of T, DHT significantly increased seminal vesicle weight in 0M males such that they were equivalent to weights in 2M males treated with T or DHT. This finding suggests that seminal vesicles in 0M males have lower concentrations of 5 alpha-reductase and, thus, a lower capacity to metabolize T to DHT which is required for normal seminal vesicle function. There were no significant effects of E2 (in combination with T or DHT) on seminal vesicle or preputial gland weight.