Distribution Of Oxytocin And Gonadotropin Releasing Hormone In Hypothamic-Pituitary-Ovary Axis In Different Physiological Cycles Milk Goats

The super sensitive immunohistochemical SP method was used to study the expression of oxytocin(OT) and gonadotropin-releasing hormone(GnRH) in the hypothalamatic-pituitary-ovary axis of dairy goats during different physiology cycle.In addition,the situ hybridization way was used to study the distribution of OTmRNA in the hypothalamus of adult estrous dairy goats.What all we done was for reseaching the function and mechanism of OT and GnRH in reproduction and regulation mechanism of Hypothalamatic-Pituitary-Gonadal axis.The major results were as follow: 1. The distribution of OT and GnRH immunoactive prodution was extensively in the hypothalamus of dairy goats during different physiology cycle.OT immunoactive prodution mainly existed in neurohypophysis and GnRH immunoactive prodution was detected in adenohypophsis.In ovary,OT immunoactive prodution only presented in the corpus luteum and GnRH was not only in the corpus luteum but also in the granulosa cell layers in antral follicles.The result suggested OT and GnRH immunoactive prodution extensively presented in the hypothalamatic-pituitary-ovary axis of dairy goats. 2. In the hypothalamatic-pituitary axis of dairy goats during different physiology cycle,the expression regulation of OT and GnRH immunoactive prodution is:less in the youth,increasing in the sexual mature,most in estrus,but decreasing in interval estrus,and more in ealy pregnancy,falling lightly in midpregnancy,gradually enhancing in late pregnancy.The change of OT and GnRH immunoactive prodution in ovary of dairy goats during different physiology cycle is:most in estrus,more in ealy pregnancy.obviously reducing in midpregnancy,and gradually recovering in late pregnancy.Comparing with the changes in ovary,the OT and GnRH immunoactive prodution expressive variety in the hypothalamatic-pituitary axis of dairy goats during different physiology cycle were unconspicuous.Above results shows OT and GnRH have a close relation with the gonad developing and reproduction.The OT and GnRH fluctuate reason may be the consequence that the hypothalamus neuroendocrine was regulated by more factors,including nerve regulation and the hormone feedback regulation. 3. During different physiology cycle,in some hypothalamus nucleus such as nucleus parevehtricularis,nuleus supra-optious,nuleus arcuatus,nucleus supra-optious diffuses,area anterior hypothalami,nucleus ventromedialis and et al,the OT and GnRH immunoactive prodution expression shows:more in estrus,sexual mature and pregnancy,less in youth and interval estrus.The results suggested these necleus were related with reproduction.But the OT and GnRH immunoactive prodution expression in some shows hypothalamus nucleus such as nucleus supramamillaris and nucleus ventrolateralis hadn't such change so we infered these nucleus may be related with other physiology fuction. 4. The less OT-immunohistochemical(OT-IR) cells and fibers were detected in adenohypophsis,which stained very weekly.This hadn't been reported in any literature.so we infered the way OT modulated the hormone secretion in adenohypophsis was likely to not merely by releasing into portal vein of the medium eminence and then to adenohypophsis to act on.And it was possiblely regulated by the adenohypophsis nerves. 5. In adult estrus dairy goats hypothalamus,OTmRNA mainly distributed over nucleus pareventricularis and nucleus supra-optious.In addition,OTmRNA were found in nucleus arcuatus,nucleus dorsomedialis,area dorsalis hypothalami,nucleus posterior hypothalami, nucleus hypothalamicus parvocellularis , nucleus periventricularis hypothalami, nucleus posterior perifornicalis,nucleus suprachiasmaticus , nucleus supra-optious diffuses, nucleus tuberomamillaris,nucleus ventrolateralis,nucleus ventromedialis and nucleus mamilaris.These results showed the distribution of OTmRNA in the hypothalamus of estrous dairy goats was extensive.Comparing with the distribution of OTmRNA in the hypothalamus of dairy goats during other physiology periods,the hypothalamic OTmRNA were increased in estrus.we infered it may be the regulation of neuroendocrinal magnocellular neurons, periventricularis neurons projecting to the hypothalamus or other brain regions and ovarian steroid hormones. 6. Some OT-IR cells and GnRH-IR cells with neurite were detected in corpus luteum,which liked neuron.And their tail-like neurites reached to the adjacent cell.These cells had the endocrinal and paracrinal function.so we infered them may be belong to DNES cells.