Ke. Lane et al., EFFECT OF COMBINED TESTOSTERONE AND ESTRADIOL-17-BETA TREATMENT ON THE METABOLISM OF E(2) IN THE PROSTATE AND LIVER OF NOBLE RATS, The Prostate, 30(4), 1997, pp. 256-262
BACKGROUND. Long-term treatment of Noble (NBL) rats with testosterone
(T) and estradiol-17 beta (E(2)) induces dysplasia in the dorsolateral
lobe (DLP) but not in the ventral lobe (VP) of the rat prostate. The
aim of this study was to determine whether metabolic conversion of E(2
) to catechol estrogens (CEs), which are potentially genotoxic, is a m
echanism of estrogen carcinogenicity in this tissue. METHODS. Male NBL
rats were treated simultaneously with T and E(2), or left untreated,
for 16 weeks after which time the liver, VP, and DLP were excised for
microsomal preparations. H-3-E(2) metabolites generated in microsomal
incubates were separated by high-performance liquid chromatography (HP
LC) and identified by coelution with known E(2) metabolites. RESULTS.
2- and 4-hydroxyestrogens were detected at high levels in hepatic micr
osomal incubates, and at extremely low levels in prostatic microsomal
incubates. T + E(2) treatment of rats did not increase the formation o
f these prostatic and hepatic metabolites. CONCLUSIONS. These results
do not support CE formation as a mediating step in estrogen-induced tu
morigenesis in the rat prostate. (C) 1997 Wiley-Liss, Inc.