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Androgen‐supported estrogen‐enhanced epithelial proliferation in the prostates of intact noble rats
Author(s) -
Leav Irwin,
Merk Frederick B.,
Kwan Paul W.L.,
Ho ShukMei
Publication year - 1989
Publication title -
the prostate
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.295
H-Index - 123
eISSN - 1097-0045
pISSN - 0270-4137
DOI - 10.1002/pros.2990150104
Subject(s) - estrogen , endocrinology , medicine , dihydrotestosterone , prostate , androgen , dysplasia , atrophy , testosterone (patch) , biology , cancer , hormone
Using a stathmokinetic in vivo metaphase‐arrest technique, we studied cell proliferation and histological changes in the ventral (VP) and dorsolateral (DLP) prostate lobes of intact Noble (Nb) rats following a 16 week treatment with testosterone (T) or 5α‐dihydrotestosterone (DHT) administered separately or in combination with various estrogens. The combined treatment of rats with T and either estradiol‐17β, estradiol‐17α, or moxestrol induced florid dysplasia and markedly elevated the mitotic index (MI) in affected regions of the DLP. In contrast, joint DHT and estrogen treatment caused only mild proliferative lesions in this lobe. The separate administration of either androgens or estrogens suppressed epithelial proliferation in both the VP and DLP, but they differed in their histological effects on these tissues. Thus DHT or T alone maintained the morphological integrity of VP and DLP, whereas E 2 ‐17β or moxestrol caused massive atrophy of both lobes. Although dysplastic foci were randomly scattered throughout the DLP, the most dramatic lesions occurred in periurethral ducts. With the exception of joint T and E 2 ‐17α treatment, which induced proliferative alterations in the VP, dysplasia was always restricted to the DLP of all animals receiving both androgens and estrogens. Concomitant comparative stathmokinetic studies of the prostates of T‐treated castrates suggest that protracted androgen‐supported estrogen stimulation of the DLP is necessary to overcome factors that normally limit cell proliferation.