Expression of androgen receptor and its co-localization with estrogen receptor-alpha in the developing pituitary gland of sheep fetus.

No information is known concerning the expression of androgen receptor (AR) and its co-localization with estrogen receptor alpha (ERalpha) in the developing pituitary of sheep fetus. In the present study, we detected AR expression and its co-localization with ERalpha in the anterior pituitary of sheep fetus from day 60 of gestation to the postnatal by dual immunochemistry. The results showed that both AR immunoreactivity (AR-ir) and ERalpha immunoreactivity (ERalpha-ir) were predominantly localized in the nuclei of LH positive gonadotropes. The cell counting results showed that the percentage of the anterior pituitary cells expressing AR fluctuated from 13.51 +/- 0.92 to 17.05 +/- 1.83% during the examined stages, but there were no significant differences between sexes and among ages examined (P > 0.05). However, the proportion of AR-ir cells containing LH markedly increased from day 60 of gestation to the neonatal (P < 0.05). The percentage of AR-ir cells expressing ERalpha-ir significantly increased from day 60 of gestation to the neonatal, respectively (P < 0.05), but no significant differences were seen between genders at each stage examined. These results indicate that both AR and ERalpha are mainly expressed in the gonadotropes of anterior pituitary gland of sheep fetuses, whereas the functions and interaction of AR and ERalpha expressions in the developing pituitary gland are required to be elucidated further.