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

Abstract

Estrogens and androgens play important roles in regulating the hormone-secreting functions of the pituitary gland by binding to their corresponding receptors. However, the expression of estrogen receptors (ERs) and the androgen receptor (AR) and the cell types containing ERs and AR in the anterior pituitary gland of adult chickens have not been well-studied. In this study, the distribution of ERα, AR and their corresponding cell types in the anterior pituitary gland of adult cockerels was detected by immunohistochemistry. The results showed that ERα was expressed in 68.63 % of luteinizing hormone (LH) producing cells but was not found in thyrotropes, lactotropes, somatotropes, corticotropes and folliculo-stellate (FS) cells. Pituitary hormone and AR double labeling results showed that about 37 % of LH cells and 50 % of thyroid-stimulating hormone (TSH) producing cells expressed AR, respectively. In contrast, less than 1 % of the somatotropes had an AR positive signal and AR signals were not detected in lactotropes, corticotropes or FS cells. In addition, there were only a few AR and ERα dual-labeled cells observed. These novel results provide evidence for a cell-specific distribution of ERα and AR in the anterior pituitary from adult cockerels by immunohistochemistry. The different distributions of ERα and AR in the LH cells suggest that the feedback-regulating mechanisms of estrogen and androgen on the pituitary hormones secretion are different. The functions and related mechanisms still need to be elucidated further.

Visfatin in the porcine pituitary gland: expression and regulation of secretion during the oestrous cycle and early pregnancy

“…The porcine pituitary gland, thanks to the presence of both classical oestrogen and progesterone receptors and non-classical membrane receptors, is sensitive to the action of oestradiol (E 2 ) and P 4 24 . Approximately 70% of pituitary gonadotrophs, responsible for LH and FSH generation, express oestrogen receptors in different species 25 – 27 . Of note, the sensitivity of the gland to steroids changes throughout the cycle.…”

Effects of Caponization on Expression of Gonadotropin-Releasing Hormone-I and Gonadotropin Subunits Genes in Roosters

“…It is well-known that estrogens and androgens influence pituitary functions by binding to the corresponding receptors in pituitary. Sun et al (2012) reported that ER α and AR was expressed in LH cells about68% and 37%, respectively, in pituitary of adult cockerels. They also deduced that ER and AR-positive cells (approximately 64%) are FSH-secreting gonadotrope.…”

“…( Burger et al , 2004 ). Sun et al (2012) reported that estrogen receptor α (ER α ) and androgen receptor (AR) are different distributions in gonadotrope cells suggest that the regulating mechanisms of estrogen and androgen on the pituitary hormones secretion are different. Local production of activin and follistatin (FS) appear to stimulate and inhibit secretion of FSH, respectively ( Winters et al , 2001 ).…”