Unexpected virilization in male mice lacking steroid 5 alpha-reductase enzymes.

Abstract:

:Mice lacking steroid 5 alpha-reductase 1 and 2 were produced by gene targeting and breeding. Male mice without 5 alpha-reductase 2 or without both enzymes had fully formed internal and external genitalia and were fertile, but had smaller prostates and seminal vesicles than controls. T accumulated to high levels in the reproductive tissues of the mutant mice. DHT administration increased seminal vesicle and coagulating gland weights in mice deficient in 5 alpha-reductase 2 and increased the weights of the prostate, seminal vesicle, and coagulating gland in animals deficient in both enzymes. An inhibitor of both 5 alpha-reductases (GI 208335X) decreased prostate and coagulating gland weights of control mice, but had no effect in those lacking 5 alpha-reductase 1 and 2. Castration reduced the sizes of these tissues in animals of all genotypes. Androgen-dependent gene expression was decreased in the seminal vesicles of mice lacking one or more 5 alpha-reductases and was restored by administration of T or DHT. Female mice missing both enzymes exhibited parturition and fecundity defects similar to those of animals without 5 alpha-reductase 1. We conclude that T is the only androgen required for differentiation of the male urogenital tract in mice and that the synthesis of DHT serves largely as a signal amplification mechanism.

journal_name

Endocrinology

journal_title

Endocrinology

authors

Mahendroo MS,Cala KM,Hess DL,Russell DW

doi

10.1210/endo.142.11.8510

subject

Has Abstract

pub_date

2001-11-01 00:00:00

pages

4652-62

issue

11

eissn

0013-7227

issn

1945-7170

journal_volume

142

pub_type

杂志文章