ESTROGEN AND THE MALE REPRODUCTIVE TRACT

雄性生殖生物学的一个基本问题是 男性体内的雌激素 我们的数据和其他数据显示雌激素 受体（ER）集中在输出小管和初始 附睾段 尽管有这些重要信息， 关于雌激素在男性中的作用知之甚少，尽管 输出小管占人类附睾头的三分之一。 我们使用ER-α基因敲除小鼠（ERKO）和 正常小鼠的抗雌激素治疗清楚地表明，雌激素 调节输出小管中的液体和离子重吸收。 这是 首次报道了雌激素在男性中的重要作用， 生殖道 根据这些和其他初步数据，我们 提出一个总体假设，即雌激素调节液体重吸收 通过直接或间接改变离子在传出小管中的作用 运输 将使用以下特定条件检验此假设 目标：1.确定抗雌激素治疗对 附睾中精子的浓度和小鼠的生育能力。 2. 测量雌激素调节的体液重吸收的幅度， 输出小管 3. 确定电中性NaCl的变化 在传出小管上皮中诱导的吸收机制 抗雌激素治疗或转基因雌激素受体破坏。 4. 确定雌激素在基因表达调节中的作用， 在传出神经中发现的参与离子转运过程的蛋白质 小管上皮 我们将检验ER功能障碍会抑制 传出小管重吸收管腔液体的能力， 在正常浓度的环境中将精子移入附睾 是精子成熟所必需的 体内和体外实验 将用于为这些研究提供生理相关性。 到 了解生理机制，小管中的液体运动 将使用微插管和微穿刺进行测量。 内吞器的超微结构分析将用于 确定抗雌激素对上皮细胞 从管腔中吸收电子密度高的粒子。 离子的作用 转运蛋白将在体外通过电压钳位 电生理学 最后，我们将确定 雌激素对体液重吸收的影响是通过基因调控介导的 在输出小管中表达。 我们已经建立了主要的 表达ER的输出小管上皮细胞培养物， 保持电生理特性与极化 上皮 这项研究将提供基本信息， 使我们能够研究针对头部的疾病过程， 并导致男性不育。

A fundamental question in male reproductive biology is the function of estrogen in the male. Our data and others have shown estrogen receptors(ER) to be concentrated in the efferent ductule and initial segment epididymidis. Despite this important information, there is little known regarding the role of estrogen in the male, even though efferent ductule occupy one-third of the caput epididymidis in humans. Our preliminary data using the ER-alpha knockout mouse (ERKO) and antiestrogen treatment of normal mice clearly indicate that estrogen regulates fluid and ion reabsorption in the efferent ductule. This is the first report of an essential function for estrogen in the male reproductive tract. Based on these and other preliminary data, we propose an overall hypothesis that estrogen regulates fluid reabsorption in efferent ductule through direct or indirect alterations in ion transport. This hypothesis will be tested using the following specific aims: 1. Determine the effects of antiestrogen treatment on the concentration of sperm in the epididymis and fertility in mice. 2. Measure the magnitude of fluid reabsorption regulated by estrogen in efferent ductules. 3. Identify alteration in the electroneutral NaCl absorptive mechanism induced in efferent ductule epithelium by antiestrogen treatment or transgenic estrogen receptor disruption. 4. Identify the role of estrogen in the regulation of gene expression for proteins involved in the ion transport processes found in efferent ductule epithelium. We will test the hypothesis that ER dysfunction will inhibit the ability of efferent ductule to reabsorb luminal fluid and thus the ability to move sperm into the epididymis in an environment of normal concentration required for sperm maturation. Both in vivo and in vitro experiments will be used to provide physiological relevance to these studies. To understand the physiological mechanisms, fluid movement in the ductule will be measured using microcannulation and micropuncture. Ultrastructural analysis of the endocytotic apparatus will be used to determine effects of antiestrogens on the ability of epithelial cells to take up electron-dense particles from the lumen. The function of ion transport proteins will be examined in vitro by voltage-clamped electrophysiology. Finally, we will determine if the effects of estrogen on fluid reabsorption are mediated by the regulation of gene expression in the efferent ductule. We have established primary epithelial cell cultures of ductuli efferentes that express ER and maintain electrophysiological properties consistent with a polarized epithelium. This research will provide basic information that will allow us to study disease processes that target the head of the epididymis and lead to male infertility.