Er-α Expression In The Hypothalamus- Pituitary-Gonad Axis Of The Bactrian Camel (Camelus Bactrianus)

The aim of this study was to examine the expression of estrogen receptor (ER-a) in the Bactrian camel’s hypothalamus-pituitary-ovary (HPO) axis and its significance. Immunohistochemistry (SABC) and Image-Pro Plus 6.0 were used to study the expression of Estrogen Receptor (ER-α). Immunohistochemical analysis revealed that the expression of the ER-a was found in all of three organs in the hypothalamus-pituitary-ovary (HPO) axis. The ER-a immunopositive neurons were found in the main hypothalamus nuclei, which were stained in various degrees. A lot of ER-a immunopositive cells were observed in the pars intermedia of the adenohypophysis. Meanwhile, a small amount of ER-a immunopositive cells were found in the pars distalis near the pars intermedia. In contrast, no ER-a expression was observed in the neurohypophysis. The ER-a immunopositive production was detected in the follicular granules, interstitial gland, corpus luteum and mesenchyme of the ovary. These results suggested that estrogen of the camel acted not only on the sexual gland, but on the various areas of the central nervous system. Thus, we speculated that ER-a took part in the regulation of reproduction, endocrine and cognition in the brain.