It is well known that testosterone is required in order to stabilize the Wolffian duct prior to its differentiation into the epididymis, vas deferens, and seminal vesicles. Testosterone exerts its effects via activation of the androgen receptor (AR), as does the 5a-reduced androgen, dihydrotestosterone (DHT). It is less clear whether the metabolites of testosterone, namely, estradiol or the major metabolite of DHT, 5a-androstane-3a, 17p-diol, have any role to play in epididymal differentiation or maturation.
Steroid receptors for both androgens and estrogens are present in the epididymis during postnatal development, and we have established that neonatal manipulation of these hormones in the rat can result in major changes in the structural differentiation of the epididymis and vas deferens during the peripubertal period; estrogens or the androgen: estrogen balance appear to be the most important factors in this. These findings raise the question of whether such structural changes are associated with altered expression of epididymal proteins such as H+-ATPase. The present study, therefore, assessed whether neonatal hormonal manipulation alters the subsequent development of cells rich in H+-ATPase during pubertal development. Manipulation of the levels and action of estrogen, androgen, or both were performed neonatally during the period of onset of the expression of H+-ATPase. The consequences of these treatments on the development of H+-ATPase-rich cells were determined in the rat epididymis at Postnatal Day 25, when the number of these cells should be at its peak.