Distribution Patterns and Developmental Changes of GnRH and GnRHR-Immunopositive Cells in the Pituitary of Ji Ning Gray Goats

Immunohistochemical strept avidin biotin-peroxidase complex (sabc) three-step method was used to investigate the distribution patterns and developmental changes of gnrh and gnrhr immunopositive (gnrh-ip and gnrhr-ip) cells in the pituitary of ji ning gray goats during 0-180 days of age. the results showed that gnrh-ip and gnrhr-ip cells were detected only in the pars distalis of adenohypophysis. there were no positive cells in the pars intermedia and neurohypophysis. gnrh-ip and gnrhr-ip cells were not observed in the anterior pituitary at birth day and 30 days of age. at 60 days, a number of gnrh-ip and gnrhr-ip cells were found in the anterior pituitary. gnrh-ip cells were pale brown which scattered or clustered around the sinusoid capillary; gnrhr-ip cells were brown and the cytomembrane was darker. the size and percentage of gnrhip and gnrhr-ip cells increased with the age growth. the numbers of gnrh-ip and gnrhr-ip cells after sexual maturity were significantly bigger than that before sexual maturity. the results above suggested that gnrh and gnrhr in the pituitary of ji ning gray goats play a pivotal role in the sexual development and sexual maturity.