Growth stimulation of the immature chick oviduct by androgens: the vagina as a new target tissue.

Testosterone when injected alone stimulates growth of the vagina but is inactive upon the other segments of the oviduct of the immature chicken. This action of testosterone can already be detected in embryos: it is expressed by the beginning of differentiation of the vaginal mesenchyme cells into smooth muscle cells. In the treated immature chicken, stimulation of growth is considerable and is specifically caused by androgens (testosterone and 5-alpha-dihydrotestosterone); the vaginal mesenchyme differentiates into two smooth muscular layers and vaginal epithelium cells differentiate into ciliated cells and goblets cells. [3H]testosterone binding has been found in the vagina of the immature chicken (data not shown). The characteristics of testosterone binding to cytoplasmic components of the chick vagina are consistent with its identity as a testosterone receptor.