Immunohistochemical localization of androgen receptors in the urogenital tracts of human embryos

Abstract

The aim of this study was to investigate androgen receptor (AR) expression in the developing human urogenital tract. The distribution of AR was examined in paraffin-embedded tissue sections of the lower urogenital tract using 55 human embryos of 8-12 weeks of gestation. Immunohistochemistry was performed for AR detection and gender was determined by polymerized chain reaction. There were no differences in the distribution of AR in male and female embryos at any stage of gestation. AR was present only in the mesenchymal tissues of the urogenital sinus at 8 weeks whilst the epithelium was negative, but after 9 weeks the epithelium also showed progressively more positive staining. In the phallus, AR staining was prominent. There was far less staining in the epithelium of the urethral groove from 8 to 10 weeks, whilst the mesenchyme of the urethral folds showed positive staining. At 11 and 12 weeks, both the urethral groove and folds showed uniform staining. The genital tubercle, genital swelling and bulbourethral gland precusors were also positively stained, although paramesonephric ducts were negative. Staining was observed in the mesonephric duct from 9 weeks. There was an absence of staining in the rectum at all stages of gestation. The expression of AR in an epithelium may be dependent upon the mesenchyme. Mesenchymal-epithelial interactions played an important role in development, as has been described in experimental animals. AR expression could play a part in the growth of the genital organs.

Identification in rats of a programming window for reproductive tract masculinization, disruption of which leads to hypospadias and cryptorchidism

“…However, testicular testosterone concentrations simply increased in parallel with fetal body weight between E15.5 and E21.5, and it has been shown previously that fetal serum testosterone concentrations are relatively stable between E17.5 and E21.5 in rats (18). Moreover, the AR was expressed in all reproductive tract tissues in both males and females at all ages studied, a pattern consistent with published data (31,45,46). Furthermore, the dose of flutamide used in these studies was 4- to 15-fold greater than that required to abolish prostate development (29) or to prevent masculinization of AGD in rats (ref.…”

The role of androgens in fetal growth: observational study in two genetic models of disordered androgen signalling

“…The AR is ubiquitously expressed as a single, common receptor. This includes amniotic cells,16 the fetal urogenital tract17 and the fetal skeleton 18. Thus androgen resistance in CAIS is not only specific to the external genitalia, but affects all tissues related to somatic growth.…”

Pharmacologic Targets on the Female Urethra

“…In the human embryos, epithelium of the urethral groove and mesenchyme of the urethral folds showed positive staining for androgen receptors [144] . However, the impact of androgens on female urethra is still under investigation.…”