The induction of the prostate gland by @entity251 or @entity586 was studied in urogenital sinuses from @entity35 @entity35 embryos explanted in organ culture. In normal development, prostatic rudiments appeared in the urogenital sinuses of 18-19 day male foetuses as epithelial buds projecting into the mesenchyme. Male urogenital sinuses from 17-5 and 18-5 day foetuses formed buds in control medium, and addition of @entity251 or @entity586 increased their number and size. In contrast, sinuses from 15-5 and 16-5 day male foetuses did not form buds in the absence of @entity3800 , while exposure to the hormones induced them de novo. A concentration of 0-0015 microgram @entity251 /ml was sufficient to elicit prostatic buds. The same effect was seen after continuous treatment with @entity251 or brief exposure to the hormone followed by cultivation in control medium. The development of the buds followed the same time sequence as in the organ in situ. @entity251 and @entity586 elicited prostatic buds in female sinuses from 15-5 to 18-5 day foetuses, but their response to @entity3800 decreased with advancing foetal age. Male and female sinuses from 15-5 day foetuses did not respond to @entity251 but formed buds after exposure to @entity586 . This difference was considered to be due to a low content or absence of 5alpha-reductase at this stage. Testes from 15-5 to 18-5 day foetuses grown in close contact with urogenital sinuses or explants of mature prostate glands induced prostatic buds or augmented the height of the prostatic epithelium. It was concluded that @entity3800 are necessary for the initiation of the @entity35 prostate gland and that the effect of @entity251 is mediated via @entity586 . The onset of 5alpha-reductase synthesis is likely to occur between days 14 and 15 of foetal life. The early androgenic activity of the testes suggests that bud formation in the older male sinuses in the absence of @entity3800 is due to exposure to endogenous @entity251 before explanation.

Induction of the XXXX prostate gland by @entity3800 in organ culture.

@entity35 :: ('10116', 'Species') :: ['rat', 'Wistar'] @entity251 :: ('MESH:D013739', 'Chemical') :: ['testosterone', 'Testosterone'] @entity3800 :: ('MESH:D000728', 'Chemical') :: ['androgens'] @entity586 :: ('MESH:D013196', 'Chemical') :: ['5alpha-dihydrotestosterone', 'dihydrotestosterone']
@entity35 :: (10116,Species) :: ['rat']
