Ikeda Yayoi, Nagai Akiko, Ikeda Masa-aki, Hayashi Shinji
Department of Anatomy, Institute of Basic Medical Sciences, University of Tsukuba, 1-1-1 Tennohdai, Tsukuba, Ibaraki 305-8575, Japan.
Endocrinology. 2002 Jan;143(1):304-12. doi: 10.1210/endo.143.1.8603.
Müllerian-inhibiting substance (MIS) is an essential factor for male sexual differentiation. In the present study, we examined whether the expression of MIS and several of its related transcription factors is altered in the ovaries of rats treated with the synthetic estrogen, E2 benzoate (EB; 10 microg/0.02 ml), from postnatal day 1 (P1) to P5. The EB-treated rats had a significantly reduced number of layered follicles at P6 in comparison with the control rats that were treated with vehicle alone. The expression levels of both MIS mRNA and protein in the granulosa cells of small growing follicles in the ovary at P6 were higher in the EB-treated rats than in the controls. These results indicate that the inhibitory effect of EB on the follicular stratification may correlate with the inappropriately increased expression level of MIS. Furthermore, the expression levels of one of its transcriptional activators, steroidogenic factor 1, and ER-beta in granulosa cells of small growing follicles were higher in EB-treated ovaries than in the control ovaries. These results suggest the role of MIS in the regulation of follicular growth and the possible involvement of steroidogenic factor 1 and/or ER-beta in this molecular cascade may contribute to postnatal ovarian development.
苗勒管抑制物质（MIS）是男性性分化的关键因素。在本研究中，我们检测了从出生后第1天（P1）至P5用合成雌激素苯甲酸雌二醇（EB；10微克/0.02毫升）处理的大鼠卵巢中MIS及其几种相关转录因子的表达是否发生改变。与仅用赋形剂处理的对照大鼠相比，经EB处理的大鼠在P6时分层卵泡数量显著减少。在P6时，经EB处理的大鼠卵巢中正在生长的小卵泡颗粒细胞中MIS mRNA和蛋白的表达水平均高于对照组。这些结果表明，EB对卵泡分层的抑制作用可能与MIS表达水平的不适当升高有关。此外，经EB处理的卵巢中正在生长的小卵泡颗粒细胞中其转录激活因子之一类固醇生成因子1和雌激素受体β（ER-β）的表达水平高于对照卵巢。这些结果提示MIS在卵泡生长调节中的作用，并且类固醇生成因子1和/或ER-β可能参与这一分子级联反应，这可能有助于出生后卵巢的发育。
