Regional differences of pheromone production in the sebaceous glands of castrated goats treated with testosterone

The primer pheromone is responsible for the "male effects" in goats and pro duced in the sebaceous glands testosterone-dependently. In the present stud y, the responses of sebaceous glands obtained from the head and rump region s of castrated goats were examined by our bioassay system after testosteron e treatment to demonstrate the presence of regional differences in the pher omone production in male goats. The testosterone treatment resulted in the marked development of sebaceous glands and the induction of pheromone bioac tivity in the head region of the goats. On the contrary, this treatment bro ught neither development of the sebaceous glands nor induction of pheromone bioactivity in the rump region. The treatment increased immunoreactivities to androgen receptors (AR) and 5 alpha -reductase in the sebaceous glands of both regions, although the activities were more apparent in the head reg ion than the rump region. These findings suggest that the primer pheromone of male goats is produced specifically in the sebaceous glands of the head region due partly to regional differences in the expression of AR and 5 alp ha -reductase mediating testosterone bioactivities.