A further contribution to the question of trophic and hormonal influences on the noradrenaline content of the male reproductive tract: effect of combined androgen and estrogen treatment of prepuberally castrated rats.

58 days old, prepuberally castrated, male rats were treated with estrogen, testosterone or a combination of both hormones for 18 days. The total noradrenaline (NA)-content of the male accessory glands was increased by the hormone treatments. This increase was smallest in the estrogen treated group and largest in the group treated with both estrogen and testosterone. The NA-concentration, however, followed the reversed picture i.e. it was largest in untreated castrated rats and smallest in the rats receiving both estrogen and testosterone. Neither treatment brought the NA-amount up to the level of uncastrated controls of the same age although the weights of the secondary sex glands of rats receiving both estrogen and testosterone exceeded those of uncastrated controls. Similar, but less definite changes were observed in vas deferens and cauda epididymidis. It is concluded that a developing target area exerts some trophic influence on the adrenergic neurons innervating it. However, the trophic influence exerted by the effector organ on the nerves is not of the kind, that the innervation density and NA-concentration of the organ always are maintained at a constant level.