REGULATION OF HUMAN MYOMETRIAL ION CHANNELS

子宫平滑肌的生理活动可以被调节 通过改变子宫肌层细胞的电特性。 在妊娠期的大部分时间里，子宫处于相对静止状态， 状态，但在足月时，子宫肌层已为强烈的活动做好准备 劳动的过程涉及其电性质的变化。 例如，人们认为， 在足月子宫肌层的准备过程中起着关键作用 怀孕是为了剧烈的劳动活动。加强 雌激素引起的电兴奋性包括gap表达的增加 连接和膜受体，最近，研究表明， 雌激素可能控制电压依赖性离子通道的合成， 大鼠子宫肌层细胞此外，兴奋性物质的存在 如催产素和前列腺素在分娩时引起 通过直接影响，立即迅速加强活动， 肌肉。拟议研究的主要总体目标是 研究电压依赖性离子通道在人类细胞中的表达调控 子宫肌层细胞，并开始使用分离的人子宫肌层细胞， 参与短期和长期的代理商的电生理学研究 离子通道行为的调节。应用分子生物学 技术，包括非洲爪蟾卵母细胞表达系统和 北方印迹法检测人子宫肌层mRNA 与在大鼠子宫RNA中发现的组织相似， 能够诱导卵母细胞中钾通道的表达， 尝试。此外，分离的子宫肌层细胞的原代培养物 将进行准备和鉴定。自发和诱发作用 将使用电流钳技术研究潜在活性。的 将研究在这些细胞中表达的钾离子通道的类型 使用补丁技术，将进行实验，以确定是否 非常缓慢地激活钾离子通道， 在离体人子宫肌层中可检测到内脏平滑肌 细胞快速作用兴奋性神经递质的电生理效应 如肽（催产素，EGF）和前列腺素等物质将被 研究了对化合物的反应，如雌激素，这需要一个 此外，我们亦会研究如何在较长时间内暴露于空气中，以发挥其效用。 使用培养的细胞进行体外培养。特别是，假设 雌激素可能会增加缓慢激活钾通道的密度 在这些细胞将被测试。像这样的研究很可能 提供对正常和异常的分子事件的深入了解 劳动组织特异性的钾离子通道 表达或调节药理学试剂， 临床上

The physiological activity of uterine smooth muscle can be regulated through alterations in the electrical properties of the myometrial cells. During most of gestation, the uterus is kept in a relatively quiescent state, but at term, the myometrium is prepared for the intense activity of labor by processes involving changes in its electrical properties. Increased activation by physiological estrogen, for example, is believed to play a crucial role in the preparation of the myometrium at term pregnancy for the intense activity of labor. The enhancement of electrical excitability by estrogen involves increased expression of gap junctions and membrane receptors, and recently, it was shown that estrogen may control the synthesis of voltage-dependent ion channels in rat myometrial cells. In addition, the presence of excitatory substances such as oxytocins and prostaglandins around the time of labor cause an immediate and rapid intensification of activity through direct effects of the muscle. The main overall objectives of the proposed studies would be to study the control of voltage-dependent ion channel expression in human myometrial cells, and to begin using isolated human myometrial cells for electrophysiological studies of agents involved in short- and long-term regulation of ion channel behavior. Using molecular biological techniques, including both the Xenopus oocyte expression system and Northern blotting, the detection of an mRNA species from human myometrial tissue similar to the one which was found in rat uterine RNA and shown capable of inducing the expression of potassium channels in oocytes will be attempted. In addition, primary cultures of isolated myometrial cells will be prepared and characterized. Spontaneous and evoked action potential activity will be studied using current-clamp techniques. The types of potassium ion channels expressed in these cells will be studied using patch techniques, Experiments will be done to determine whether very slowly activating potassium channels like those present in rat visceral smooth muscle can be detected in isolated human myometrial cells. The electrophysiological effects of rapidly acting excitatory substances such as peptides (oxytocin, EGF) and prostaglandins will be studied. The responses to compounds such as estrogen which require a longer period of exposure to exert their effects will also be examined in vitro using the cultured cells. In particular, the hypothesis that estrogen may increase the density of slowly activating potassium channels in these cells will be tested. Studies such as these are likely to provide insight into molecular events underlying normal and abnormal labor. It seems likely that potassium channels which show tissue-specific expression or regulation of pharmacological agents which could be used clinically.