Effects of mifepristone administered at metaestrus on ¦Âª²EP neurons in hypothalamus arcuate nucleus and anterior pituitary in rats

    ZHANG Hua1,3, WANG Jianª²Wei2, LI Jianª²Ping3, ZHAO Xiaoª²Xia3

    1Chongqing Health Center for Women and Children, Chongqing 400013, China, 2Department of Histology and Embryology, Chongqing University of Medical Sciences, Chongqing 400016, China, 3Department of Obstetrics & Gynecology, First Hospital of Hebei North Medical College, Zhangjiakou 075000, China

    ¡¾Abstract¡¿ AIM: To study the effect of mifepristone administered at metaestrus on ¦Âª²EP neurons in hypothalamus arcuate nucleus(ar) and anterior pituitary in rats. METHODS: Adult female Wister rats having 4ª²day estrus cycles were randomly divided into normal control (NC) group and mifepristone administed at metaestrus (AM) group. Sternberger¬ðs PAP method was used to detect the changes of ¦Âª²EP neurons in hypothalamic arcuate nucleus and anterior pituitary. The morphological changes of ovary and endometrium in rat were also observed. RESULTS: ¢Ù¦Âª²EP neuron number in hypothalamic arcuate nucleus in AMG was higher than that in NCG at diestrus (P<0.01) and proestrus (P<0.01). ¢ÚThe mean number of ¦Âª²EP neuron in anterior pituitary in AGM was more than that in NCG at diestrus (P<0.05) and proestrus (P<0.01). ¢Û Morphologically, there were many growing follicles at diestrus and many graafian follicles at proestrus in NCG while there were fewer growing follicles at expectant diestrus and their dia was smaller in AMG. No graafian follicle was observed at expectant proestrus. ¢Ü As for gland number per transection, dia of gland cavity, highness of gland cell and thickness of endometrium, the number of the four parameters was higher at proestrus than that at diestrus (P<0.01) in NCG. After administering mifepristone at metaestrus, all of the parameters at expectant diestrus in AMG were significantly higher than those at diestrus in NCG, and then all of them decreased at expectant proestrus, but gland number per transection and dia of gland cavity showed no significant changes. CONCLUSION: Mifepristone used at metaestrus can change the numbers of ¦Âª²EP neurons in hypothalamus arcuate nucleus and anterior pituitary in rats. Mifepristone administered at metaestrus can inhibit the follicle development and delay the endometrial maturation. The changes indicate that the central nervous system can be affected by mifepristone, which will in turn affect ovary and endometrium. ......