GnRH在妊娠期黄牛下丘脑—垂体—卵巢轴中的表达

Expression of GnRH in the Hypothalamic-Pituitary-Ovarian Axis of the Pregnant Cattle

旨在研究促性腺激素释放激素(GnRH)在妊娠期黄牛下丘脑—垂体—卵巢轴中的表达,探索其与妊娠的关系。运用免疫组化ABC法和图像分析软件Image-ProPlus6.0对妊娠期黄牛下丘脑、垂体和卵巢组织中GnRH的表达情况进行研究。结果表明:(1)在下丘脑中,GnRH阳性神经元主要分布于下丘脑前核(AH)、乳头体内侧核(MMN)、腹内侧核(VMN)、弓状核(ARC)及室旁核(PVN),其中AH和MMN阳性产物分布面积(S)和累计光密度(IOD)值均较大(SAH>SMMN>SVMN>SARC>SPVN和IODAH>IODMMN>IODVMN>IODARC>IODPVN;P<0.001);(2)在腺垂体中,存在大量GnRH阳性细胞,而神经垂体中仅有GnRH阳性纤维;(3)在卵巢中,GnRH阳性产物分布在妊娠黄体、卵泡颗粒细胞及间质中。结果提示,在下丘脑各核团中,AH和MMN的GnRH可能对维持黄牛妊娠起主导作用,而垂体和卵巢中GnRH可能是通过自分泌和旁分泌方式与相关激素协同作用来维持妊娠黄牛的激素平衡及内环境稳态等。

The experiment was conducted to study the expression of gonadotropin releasing hormone（GnRH） in the hypothalamic-pituitary-ovarian axis of the pregnant cattle,and to explore its function.The expression of GnRH in the hypothalamus,pituitary and ovary of the pregnant cattle and performed a detailed analysis were examined by immunohistochemical ABC and Image-Pro Plus 6.0.The results showed as following：（1） GnRH immunopositive production were found in the anterior hypothalamic nucleus（AH）,medial mammillary nucleus（MMN）,ventromedial nucleus（VMN）,arcuate nucleus（ARC） and periventricular nucleus（PVN）.Sum area（S） and IOD of GnRH immunopositive production in the AH and MMN are larger in the hypothalamic nucleus（SAH SMMN SVMN SARC SPVN and IODAH IODMMN IODVMN IODARC IODPVN;P0.001）;（2） GnRH-positive cells are mainly distributed in the anterior pituitary and GnRH-positive nerve fibers were only observed in the neurohypophysis;（3） GnRH immunopositive production was found in the granulosa cells,stroma of ovary（stroma ovarii） and corpus luteum of pregnancy（corpus luteum verum） in the ovary.The results suggested that GnRH-positive neurons in AH and MMN may play a important role in the maintenance of pregnancy in cattle;in the pituitary and ovary,GnRH may have important roles in hormone homeostasis and regulation of pregnancy in cattle by the way of autocrine and paracrine.