Study On Reproductive Regulation Mechanism In Pituitary-ovary During Breeding And Nonbreeding Season Of Laiwu Black Goat

The mammalian reproduction action mainly reside in the pituitary-ovary axis. After receiving the signals of gonadotropin releasing hormone(GnRH) from hypothalamus ,the gonadotropic cells in pars distalis hypophyseos secrete reproductive key hormone--FSH and LH ,which specially bind with the corresponding G protein-coupled receptors(GPCR) of target cell in the ovary. The membrane receptor--FSHR and LHR are mediated by GPCR which can mediate and stimulate CAMP system. Consequently, the gonadotropine signals are transferred into cell. The estrogen secreted by ovary has a feedback regulation to the FSH and LH secretion and releasing in pituitary . Difference of photoperiod cause pituitary-ovary axis function a alternate change in seasonal-evident areas,which affect the secretion of FSH or LH and gonad regulation . Laiwu black Goat is the superordinary endemic breed of Shandong province. The sexual maturation of Laiwu Black Goat is approximately 4~5 mouth. Its initial mating is approximately 10 mouth. It has extensive purpose such as meat,velvet,wool and leather. Furthermore,it is accommodate the grazing condition of mountain area. Laiwu Black Goat belongs typical seasonal estrous mammal. illumination seasonal diversity is evident in its breeding place.Making FSH and LH seasaonal secretion and regulation in pituitary-ovary axis as a model,the study tried to reveal the seasonal reproductive and endocrine regulatory mechanism of the periodic breeding mammals by comparing ssecretion ,level,ultrastructure of gonadotropic cell and its corresbonding receptors between breeding season and nonbreeding season.Experiment 1 The FSH,LH radioimmunoassay in pituitary content and circulating-blood plasma of Laiwu black Goat during the breeding season and nonbreeding season.