Localization of estrogen receptors-alpha and -beta and androgen receptor in the human growth plate at different pubertal stages.

Sex steroids are required for a normal pubertal growth spurt and fusion of the human epiphyseal growth plate. However, the localization of sex steroid receptors in the human pubertal growth plate remains controversial. We have investigated the expression of estrogen receptor (ER) alpha, ERbeta and androgen receptor (AR) in biopsies of proximal tibial growth plates obtained during epiphyseal surgery in 16 boys and eight girls. All pubertal stages were represented (Tanner stages 1-5). ERalpha, ERbeta and AR were visualized with immunohistochemistry and the number of receptor-positive cells was counted using an image analysis system. Percent receptor-positive chondrocytes were assessed in the resting, proliferative and hypertrophic zones and evaluated for sex differences and pubertal trends. Both ERalpha- and ERbeta-positive cells were detected at a greater frequency in the resting and proliferative zones than in the hypertrophic zone (64+/-2%, 64+/-2% compared with 38+/-3% for ERalpha, and 63+/-3%, 66+/-3% compared with 53+/-3% for ERbeta), whereas AR was more abundant in the resting (65+/-3%) and hypertrophic zones (58+/-3%) than in the proliferative zone (41+/-3%). No sex difference in the patterns of expression was detected. For ERalpha and AR, the percentage of receptor-positive cells was similar at all Tanner pubertal stages, whereas ERbeta showed a slight decrease in the proliferative zone during pubertal development (P<0.05). In summary, our findings suggest that ERalpha, ERbeta and AR are expressed in the human growth plate throughout pubertal development, with no difference between the sexes.

Bone mass and body composition of adult women with congenital virilizing 21-hydroxylase deficiency after glucocorticoid treatment since infancy.

AIM: To study bone mass, body composition and androgenic/anabolic activity in adult women with virilizing congenital adrenal hyperplasia (CAH) treated with glucocorticoids since infancy and to relate this to the postmenarcheal glucocorticoid impact. PATIENTS AND METHODS: Thirteen adult women with virilizing CAH treated with gluco- and mineralocorticoids but otherwise medicine-free were investigated with respect to bone mineral content, body composition by dual energy X-ray absorptiometry and endocrine status. In addition an index of accumulated postmenarcheal exogenous glucocorticoid impact was calculated. Seven of the patients had regular menstrual periods, and six were oligomenorrheic but responded with withdrawal bleedings on cyclic progestagens. The data for the patients were compared with those of age-matched healthy reference subjects. RESULTS: In spite of their shorter stature, CAH patients were significantly heavier and had a significantly higher body mass index and fat/lean body mass ratio than the controls. Their bone mineral area density (BMD) was significantly lower than that of the controls. Serum concentrations of androgens were subnormal in all except two of the patients. Strong negative associations were found between BMD and the calculated index of accumulated postmenarcheal glucocorticoid dose but not between BMD and circulating androgen levels. CONCLUSION: The results indicate that glucocorticoids were administered in excess in most of the patients, resulting in subnormal levels of adrenocortical androgens, increased body fat and bone demineralization. Increased catabolic activity due to hypercortisolism rather than decreased androgenic/anabolic steroids is probably the major cause of the subnormal BMD in the treated CAH patients.

Haplotypes of the steroid 21-hydroxylase gene region encoding mild steroid 21-hydroxylase deficiency.

Haplotypes of the complement 4 (C4) and steroid 21-hydroxylase [21-OHase; steroid hydrogen-donor: oxygen oxidoreductase (21-hydroxylating), EC 1.14.99.10] repeated gene complex were studied in nine families with at least one member affected with a mild form of 21-OHase deficiency. DNA probes from different parts of the repeated C4/21-OHase unit were used to follow the segregation of hybridization patterns in the families. Ten structurally distinct haplotypes of the C4/21-OHase gene region were identified, and the encoded phenotype was assigned to 34 of the 36 C4/21-OHase haplotypes. Four structurally different haplotypes with three C4/21-OHase repeat units were found. Eight of the nine haplotypes found with triplications of the C4/21-OHase repeat unit encoded the mild form of 21-OHase deficiency, whereas one particular triplicated haplotype encoded a severe form of the disease. In one case the mild form of 21-OHase deficiency was encoded by a haplotype with a single C4/21-OHase repeat unit. Mild 21-OHase deficiency was predicted in a patient by the presence of a triplicated haplotype. The finding of deranged 21-OHase genes on all triplicated C4/21-OHase haplotypes indicate that most of these common haplotypes carry mutated 21-OHase genes, and thus may cause functional polymorphism of general importance in the population.