ESTROGEN AND THE MALE REPRODUCTIVE TRACT

男性生殖生物学中的一个基本问题是 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)集中在传出小管和起始部 附睾节。尽管有这些重要的信息，但有 对雌激素在男性体内的作用知之甚少，尽管 人附睾头的1/3由传出小管构成。 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 调节传出小管中的液体和离子的重吸收。这是 雌激素在男性体内的重要作用首次报道 生殖道。根据这些和其他初步数据，我们 提出雌激素调节体液重吸收的总体假设 在传出小管中通过离子的直接或间接改变 运输。这一假设将使用以下特定的方法进行验证 目的：1.确定抗雌激素治疗对 附睾精子密度与小鼠生育力的关系。2. 测定雌激素对大鼠体液重吸收的调节作用 传出小管。3.确定电子中和氯化钠的变化 黄曲霉毒素诱导传出小管上皮吸收机制的研究 抗雌激素治疗或转基因雌激素受体阻断。4. 确定雌激素在基因表达调控中的作用 在传出细胞中发现的参与离子运输过程的蛋白质 小管上皮细胞。 我们将检验内质网功能障碍会抑制这种能力的假设 传出小管重新吸收腔内液体的能力 在正常浓度的环境中将精子移入附睾 精子成熟所必需的。包括体内和体外实验 将被用来为这些研究提供生理学相关性。至 了解导管内液体运动的生理机制 将使用微插管和微穿刺法进行测量。 内吞器官的超微结构分析将用于 测定抗雌激素对上皮细胞能力的影响 从管腔中吸收电子密度高的粒子。离子的作用 转运蛋白将通过电压钳制在体外进行检测 电生理学。最后，我们将确定 雌激素对体液重吸收的调控是由基因介导的 在传出小管中表达。我们已经建立了初选 体外培养表达ER和ER的传出小管上皮细胞 保持电生理特性与极化的 上皮组织。这项研究将提供基本信息，将 允许我们研究以头部为目标的疾病过程 并导致附睾症和男性不育。

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.