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

Abstract

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.

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“…An impressive number of recent studies have underlined the fact that sex steroids are inXuential in biological processes in a wide variety of tissues from reproductive tracts of males and females to non-reproductive tissues including cardiovascular, urinary, immune, gastrointestinal, musculoskeletal tissue (e.g., Kalbe et al 2007;Yuan et al 2007;Toth et al 2008). In the nervous system, estrogen and androgen receptors are found, and diverse eVects of the steroids in diVerent parts of the central and peripheral nervous system have been described (see Luo et al 2008).…”

Ontogeny of estrogen receptor alpha, estrogen receptor beta and androgen receptor, and their co-localization with Islet-1 in the dorsal root ganglia of sheep fetuses during gestation

“…The primary antibodies for IHC were rabbit anti-ER (Ab-17, Labvision, Fremont, CA, USA), anti-ER (#06-629, Upstate Biotechnology, USA) and anti-AR (PG-21, Upstate, NY, USA) polyclonal antibodies, which had been used to detected ER (Liu et al 2005), ER (Tian et al 2004) and AR (Yuan et al 2007) in sheep pituitary, testis and pituitary, respectively, in our laboratory. The procedure used to determine ERs and AR expressions was performed as described previously (Luo et al 2004;Yuan et al 2007).…”

“…The procedure used to determine ERs and AR expressions was performed as described previously (Luo et al 2004;Yuan et al 2007). In brief, the sections were dewaxed and rehydrated, and antigen retrieval was performed by microwaving the sections for 20 min (4 £ 5 min) at full power in 0.01 M sodium citrate buVer (pH 6.0).…”

Cell-specific distributions of estrogen receptor alpha (ERα) and androgen receptor (AR) in anterior pituitary glands from adult cockerels as revealed by immunohistochemistry

“…In addition, AR is predominantly located in the gonadotropes of mammals (Kimura et al 1993). Our recent report shows the colocalization of ERα and AR in the anterior pituitary gland of sheep fetuses, mainly in gonadotropes (Yuan et al 2007). …”