In adult life, the type 2 isozyme of 11␤-hydroxysteroid dehydrogenase (11␤HSD2) protects the mineralocorticoid receptor (MR) from glucocorticoid by inactivating cortisol to cortisone. 11␤HSD2 activity has been reported in human fetal tissues, where glucocorticoids may impair fetal growth yet are also required for normal fetal development. Using digoxigenin-labeled complementary ribonucleic acid (RNA) probes and an in-house 11␤HSD2 antiserum, we have analyzed the expression of 11␤HSD2, MR, and glucocorticoid receptor (GR) in human fetal tissues of gestational age 6 -17 weeks (n ϭ 15). 11␤HSD2 expression was absent at gestational age 6ϩ weeks, but was expressed in abundance in many fetal tissues between 8 -12 weeks. At this time, 11␤HSD2 colocalized with GR messenger RNA (mRNA) expression in metanephros, gut, muscle, spinal cord and dorsal root ganglia, periderm, sex chords of testis, and adrenal. In particular within fetal kidney, intense expression of 11␤HSD2 and GR mRNA was observed over Bowman's capsule and the vascular tufts of developing glomeruli as they migrated from the surface of the kidney to the inner cortex. Only lung and adrenal medullary rests demonstrated high levels of GR mRNA but low levels of 11␤HSD2. 11␤HSD2 mRNA and immunoreactivity staining patterns were similar, with the exception of the fetal adrenal, where mRNA was localized to the outer definitive zone but immunoreactivity was localized to the inner fetal zone. Colocalization of 11␤HSD2 (and GR mRNA) with MR mRNA was observed principally within epithelial cells of collecting ducts, particularly after 16 weeks gestation when the pattern of distribution of 11␤HSD2 became more adult in nature. High levels of MR mRNA were observed within developing bone.The data indicate that 11␤HSD2 in fetal life principally modulates ligand access to the GR in most fetal tissues, notably glomeruli and tubules in the developing kidney, testis, and periderm, and this may be have ramifications for fetal sodium homeostasis and differentiation. The development of tissues previously shown to have a critical requirement for glucocorticoids, such as lung and adrenal medulla, is facilitated by the expression of GR mRNA, but not 11␤HSD2. The expression of MR mRNA in high abundance in bone suggests a role for corticosteroids in human bone development, and the low/absent expression of 11␤HSD2 at this site suggests that it is functionally acting as a GR. (J Clin Endocrinol Metab 83: 4490 -4497, 1998)

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.

This study demonstrates that immunoreactive AR protein is present in a wide variety of human first trimester fetal tissues and shows the potential for androgen affecting tissues, which are mostly not considered to be androgen dependent. Moreover, it implies that androgen might act as a trophic factor and affect the early development of these organs rather than simply sexual differentiation.

The specific pattern of AR expression implies a key role in gonadal development. However, the pattern of staining was similar in the gonads at 8 and 9 weeks in both sexes, although staining persisted longer in the testis until the 10th week. AR expression, therefore, is not a key determinant of human gonadal differentiation.

Summary— The diagnosis of interstitial cystitis (IC) is not usually considered in patients with idiopathic instability. Because histamine provokes detrusor contractions in vitro, we assessed detrusor mast cell counts in 29 females with refractory instability. Raised mast cell counts (> 28/mm2 of detrusor muscle, consistent with a histological diagnosis of IC) were found in 29% of such cases. Thus cystoscopy and bladder biopsy should be considered in patients with idiopathic instability which fails to respond to anticholinergic drugs, as alternative therapy may be useful. Patients with refractory instability and normal detrusor mast cell counts often gave a history of prolonged childhood nocturnal enuresis (55% of cases); in contrast, patients with intractable instability and abnormally high mast cell counts seldom gave such a history (12%). These trends may give some insight into the aetiology of idiopathic instability—“congenital” or acquired?