中文摘要：

本试验采用免疫组化和放射免疫测定的方法对Orexin B在1月龄健康苏钟猪和和性成熟青年母猪下丘脑-垂体-性腺（HPG）轴的分布定位及其在HPG轴各级水平的直接分子生物学作用进行了研究。结果显示,Orexin B在下丘脑、垂体和性腺均有分布。在下丘脑的分布比较广泛,其中以穹隆周区、外侧区、背内侧核和后区的Orexin B免疫阳性神经元分布最为密集,而下丘脑前区、视前区和视交叉上核的Orexin B免疫阳性神经元分布较少。在垂体Orexin B主要分布在腺垂体的远侧部和中间部的内分泌细胞内。在性腺器官,Orexin B主要分布在初级卵泡、次级卵泡的颗粒细胞以及卵母细胞的细胞质和睾丸、附睾间质细胞内;用不同剂量的Orexin B处理体外培养的下丘脑脑片、腺垂体细胞和卵巢颗粒细胞,其中1000nmol·L-1剂量组Orexin B能极显著的刺激GnRH的释放（P〈0.01）,100和1000nmol·L-1剂量组能显著（P〈0.05）刺激LH和E2的释放。结果表明Orexin B在HPG轴各级水平直接参与猪生殖活动的调节。

英文摘要：

The experiment was conducted to investigate the distribution of Orexin B in the hypothalamo-pituitary-gonadal（HPG） axis of 1-month-old Suzhong swine and the sexual maturity sow and its direct biological actions in vitro by immunohistochemical technique and radioimmunoassay.The result showed that Orexin B-immunoreactive neurons localized within the hypothalamus,mainly in the perifornical nucleus（PeF）,the lateral hypothalamic area（LHA）,dorsomedial hypothalamic nucleus（DMH）,and posterior hypothalamic area（PH） and with a sparser distribution in the preoptic,anterior hypothalamic area（AH） and suprachiasmatic nucleus.In pituitary,Orexin B localized in endocrine cell of adenohypophysis pars distalis and intermedia.In gonad,Orexin B distributed in granular cell of primary and secondary follicle and cytoplasm of oocyte,leydig cell of the testis and epididymis.The hypothalamic plants,anterior pituitary cells and granular cell were challenged with 1,10,100 and 1 000 nmol·L-1 Orexin B and GnRH,LH and E_2 were measured after treatment.Compared to control,1 000 nmol·L-1 dose Orexin B significantly increased（P0.01）GnRH secretion,100 and 1 000 nmol·L-1 doses of Orexin B significantly stimulated（P0.05）LH and E_2 secretion.These results demonstrated that Orexin B regulated reproduction of porcine in every level of HPG axis.