HORMONAL CONTROL OF UTERINE MUSCLE K-CHANNEL MRNA

子宫肌 K 通道 mRNA 的激素控制

• 批准号: 3327154
• 负责人: MARY B BOYLE
• 金额: $ 7.25万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-05-01 至 1991-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3327154
• 关键词: complementary DNA; egg /ovum; estrogens; hormone regulation /control mechanism; immunofluorescence technique; messenger RNA; muscle contraction; myometrium; potassium channel; smooth muscle; tissue /cell culture; voltage /patch clamp

DESCRIPTION: (Adapted from the Investigator's Abstract) The overall long-term objective of the proposed studies is to understand the molecular mechanisms which control electrical activity in uterine smooth muscle and to identify molecular targets which might be useful in the management of abnormal labor. The apparent induction by estrogen of a myometrial mRNA species which causes expression of a very slow voltage-dependent potassium current in Xenopus oocytes has previously been demonstrated. This mRNA species is detectable at term and proestrus but not at midgestation or metestrus. It was hypothesized that this mRNA species encodes a smooth muscle K+ channel whose level of expression varies during the estrous cycle and pregnancy depending upon estrogen levels. The effect of increasing expression of the slowly activating K+ current may be to enhance membrane excitability by bringing the membrane potential into an optimum range for the operation of voltage-dependent currents necessary for generating spontaneous activity. The main question to be addressed by the proposed studies is: What is the role of changes in the expression of the slowly activating potassium current in the regulation of myometrial excitability by estrogen? First, the sequence encoding the slow K channel will be determined. Full-length cDNA clones for the slow K+ channel will be isolated from a uterine cDNA library and expressed in xenopus oocytes. Second, the physiological regulation of this mRNA species will be studied. The tissue-specific and hormone-regulated expression of the mRNA species encoding the slow K+ channel will be characterized using nucleic acid hybridization methods. Third, the effect of the mRNA regulation on the numbers of K+ channels in the myometrial cells will be examined. Single potassium channels will be studied in acutely dissociated uterine smooth muscle cells using patch techniques. Finally, the effect of suppressing translation of the K channel mRNA on the transformation of electrical properties by estrogen will be examined using hybrid-arrest techniques in myometrial cells treated with estrogen in vitro.

描述：（改编自研究者摘要）总体 拟议研究的长期目标是了解分子 控制子宫平滑肌电活动的机制， 以确定可能用于管理的分子靶点， 异常分娩 雌激素对子宫肌层mRNA的明显诱导 引起非常缓慢的电压依赖性钾离子表达的物种 非洲爪蟾卵母细胞中的电流先前已被证实。 该mRNA 种属在足月和发情前期可检测到，但在妊娠中期或 动情后期。 据推测，这种mRNA种类编码一种平滑的 在动情周期中表达水平变化的肌肉K+通道 和怀孕取决于雌激素水平。 性提高的效果 慢激活K+电流的表达可能是通过增强细胞膜电位， 兴奋性，使膜电位进入最佳范围， 产生所需的电压依赖电流的操作 自发活动 拟议的 研究的是：什么是缓慢的表达变化的作用 激活钾电流调节子宫肌层兴奋性 通过雌激素？ 首先，对慢K通道进行编码的序列将是 测定 慢K+通道的全长cDNA克隆将在 从子宫cDNA文库中分离并在爪蟾卵母细胞中表达。 其次，将研究这种mRNA种类的生理调节。 mRNA种类的组织特异性表达和表达调控 编码慢K+通道将使用核酸 杂交方法 第三，mRNA调控对细胞增殖的影响。 将检查子宫肌层细胞中K+通道的数目。 单个 钾通道将在急性分离的子宫平滑肌细胞中进行研究。 使用补丁技术的肌肉细胞。 最后，抑制 K通道mRNA的翻译对电性转化的影响 雌激素的特性将使用混合捕获技术进行检查， 体外雌激素处理的子宫肌层细胞。