GAP JUNCTIONS & ION CHANNELS IN CORPUS CAVERNOSUM

缝隙连接

• 批准号: 2430204
• 负责人: George Joseph Christ
• 金额: $ 22.88万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-06-01 至 1999-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2430204
• 关键词: action potentials; calcium channel; electrophysiology; fluorescent dye /probe; gap junctions; gene expression; human subject; immunoelectron microscopy; immunofluorescence technique; impotence; membrane channels; messenger RNA; muscle cells; muscle contraction; muscle relaxation; muscle tone; northern blottings; penis disorder; penis erection; potassium channel; second messengers; smooth muscle; tissue /cell culture; voltage /patch clamp; western blottings

Erectile dysfunction is a major health problem that has a dramatic impact on the quality of life of many men and their sexual partners. Moreover, erectile dysfunction represents a spectrum of disease, ranging from partial to complete impotence, and affecting an estimated 18-30 million American men greater than or equal to 40 years of age. Medical treatment of this prevalent disease resulted in 400,000 outpatient visits and 30,000 hospital admissions, at total cost of $146 million in 1985 alone. Incomplete corporal smooth muscle relaxation is now widely recognized as a significant etiologic factor in a large proportion of impotent men. The general consensus is that incomplete corporal smooth muscle relaxation severely compromises trapping of blood in the corporal sinuses (because of incomplete closure of the venous outflow), resulting in a lack of rigidity. This condition is commonly referred to as corporal veno- occlusive erectile dysfunction. In vitro studies have documented that isolated human corporal tissue strips and cultured corporal smooth muscle cells provide a valid model for studying at least some aspects of the modulation of corporal smooth muscle tone in vivo. Observations both in vitro and in vivo demonstrated that intercellular communication through gap junctions, and current flow through membrane ion channels (i.e., namely Ca & K channels) are important modulators of corporal smooth muscle tone, and therefore, of erectile capacity. It seems that regardless of the diversity of causes of erectile dysfunction related to incomplete corporal smooth muscle relaxation, their effects might still be explained via their direct or indirect impact on gap junctions, K channels or Ca channels. Thus, in many ways, the improved understanding, diagnosis and treatment of erectile dysfunction is largely dependent on more detailed knowledge of how physiologically relevant drugs modulate these primary effectors of corporal smooth muscle tone. To directly address this issue we shall: l: a) Conduct electrophysiological studies on enzymatically dispersed and cultured corporal smooth muscle cells to evaluate the role of intercellular current flow in propagating and amplifying signals in the corpora. b) Microinject cultured and enzymatically dissociated cells as well as isolated tissue strips with gap junction permeant dyes and second messenger molecules to assess the role of metabolic coupling in propagating and amplifying signals in the corpora. c) Conduct molecular biological and immunocytochemical studies to characterize gap junctions between smooth muscle cells in situ and in culture. 2) Use patch clamp techniques to characterize the K and Ca channels in enzymatically dispersed and cultured corporal smooth muscle cells. 3) Assess action potential generation in vitro, using the sucrose gap technique.

勃起功能障碍是一个主要的健康问题，有戏剧性的影响， 对许多男性及其性伴侣的生活质量的影响。此外，委员会认为， 勃起功能障碍代表了一系列疾病， 部分至完全阳痿，估计影响1800万至3000万人， 美国男性大于或等于40岁。医疗 这一流行病的发病率导致40万门诊病人和3万 住院费用，单是一九八五年一年，就达一亿四千六百万元。 不完全的身体平滑肌松弛现在被广泛认为是 一个重要的病因在很大比例的男性阳痿。的 普遍的共识是，不完全的身体平滑肌松弛 严重损害了身体鼻窦中的血液滞留（因为 静脉流出的不完全闭合），导致缺乏 刚度这种情况通常被称为身体静脉- 闭塞性勃起功能障碍体外研究已经证明， 分离的人身体组织条和培养的身体平滑肌 细胞提供了有效的模型，用于研究细胞的至少一些方面。 调节体内的体平滑肌张力。观察结果， 体外和体内研究表明，细胞间通讯通过 间隙连接和流过膜离子通道的电流（即， 即Ca和K通道）是体平滑肌的重要调节剂 因此，勃起能力。看来，不管 勃起功能障碍的原因有哪些？ 平滑肌松弛，它们的作用仍然可以通过它们的 直接或间接影响缝隙连接、K通道或Ca通道。 因此，在许多方面，提高对疾病的理解、诊断和治疗， 勃起功能障碍在很大程度上依赖于更详细的知识， 生理相关药物如何调节这些主要效应物， 体平滑肌张力为了直接解决这个问题，我们应该：l： a）对酶促分散的和 培养的海绵体平滑肌细胞，以评估 在细胞内传播和放大信号的细胞间电流 语料库B）显微注射培养的和酶促解离的细胞， 以及具有间隙连接渗透染料的分离的组织条， 信使分子，以评估代谢偶联在 在语料库中传播和放大信号。c）传导分子 生物学和免疫细胞化学研究来表征缝隙连接 平滑肌细胞在原位和培养中的差异。2)使用膜片钳 技术来表征钾和钙通道在酶 分离培养的海绵体平滑肌细胞。3)评估行动 在体外的潜力代，使用蔗糖间隙技术。