OBSTRUCTION INDUCED CHANGES IN URINARY BLADDER MUSCLE

梗阻引起的膀胱肌肉变化

• 批准号: 6498180
• 负责人: Robert S Moreland
• 金额: $ 23.23万
• 依托单位: DREXEL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-01 至 2004-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6498180
• 关键词: adenosinetriphosphatase; biological signal transduction; calcium flux; calcium indicator; calcium ion; cytoskeletal proteins; laboratory rabbit; mitogen activated protein kinase; muscle contraction; myosins; phosphorylation; photolysis; protein kinase; protein kinase C; protein structure function; smooth muscle; urinary bladder; urinary tract obstruction

DESCRIPTION (Adapted from the Applicant's Abstract): Obstruction of the urethra results in numerous alterations in the urinary bladder that impair both its storage and emptying properties. The detailed molecular mechanisms responsible for these changes in function associated with obstruction-induced remodeling have not been clearly delineated. This research project is based upon the hypothesis that the depression function of the obstructed bladder is the result of alterations in both excitation-contraction coupling (Ca2+-availability) and the contractile apparatus (Ca2+-dependent activity) in detrusor muscle. To test this hypothesis, the following specific aims will be addressed using strips of detrusor muscle obtained from normal, decompensated, and compensated rabbit bladder. Aim 1: To correlate the force-velocity-length relations of intact and skinned detrusor muscle associated with bladder obstruction and its reversal. This aim will determine the mechanism of altered active and passive mechanics at the tissue, cell and cross- bridge level. Chemically skinned muscle strips will allow for the precise and direct control of the environment surrounding the contractile apparatus, bypassing the normal excitation-contraction pathway. Aim 2: To determine the relationship among agonist concentration, cytoplasmic (Ca2+) and the time course of contraction. Laser photolysis of caged-compounds will be used to initiate contraction while monitoring the intracellular (Ca2+) with Indo-1. This aim will determine if the altered contractility is due to altered calcium mobilization. Aim 3: To determine the time course of myosin light chain phosphorylation, (Ca2+) and isometric force in intact and myosin light chain phosphorylation, actin-activated myosin ATPase activity and isometric force in permeabilized tissues during various stimuli. This aim will test for alterations in the coupling of the Ca2+ signal to contractile activation. Aim 4: To determine the significance of other regulatory signaling pathways. The protein kinase C, mitogen-activated protein kinase, calesmon phosphorylation cascade will be measured. This aim will determine if the loss of maintained contractile force in the decompensated bladder is due to alterations in steps important in thin filament regulation. The results of these studies will elucidate the specific steps of excitation-contraction coupling that are associated with bladder dysfunction. Moreover, the results of these studies will also determine which alterations in contractile or regulatory proteins are associated with bladder remodeling and will provide a more complete understanding of the cellular and molecular mechanisms responsible for the depressed bladder function associated with outlet obstruction.

描述（改编自申请人的摘要）： 尿道导致膀胱的许多改变， 损害其储存和排空性能。详细的分子 负责这些功能变化的机制与 阻塞引起的重塑尚未明确描述。这 一项研究项目是基于这样的假设，即抑郁症 梗阻膀胱的功能是两者改变的结果。 兴奋-收缩偶联（Ca 2 +-可用性）和收缩 逼尿肌中的Ca 2+依赖性活动。为了验证这一 假设，将使用条带解决以下具体目标 逼尿肌的肌肉，从正常的，失代偿的，和补偿 兔子膀胱目的1：关联力-速度-长度关系 与膀胱相关的完整和去皮的逼尿肌 阻碍及其逆转。这一目标将决定 改变了组织、细胞和跨组织的主动和被动机制， 桥的水平。化学皮肤肌肉条将允许 精确和直接控制周围的环境， 收缩器，绕过正常的兴奋-收缩 通路目的2：确定促效剂之间的关系 浓度、细胞质（Ca 2+）和收缩的时间过程。 笼状化合物的激光光解将用于引发收缩 同时用Indo-1监测细胞内Ca ~（2+）。这一目标将 确定收缩力的改变是否是由于钙的改变 动员。目的3：测定肌球蛋白轻链的时程 完整和肌球蛋白光下的磷酸化、（Ca 2+）和等长力 链磷酸化，肌动蛋白激活的肌球蛋白ATP酶活性， 在各种刺激期间透化组织中的等长力。这 aim将测试Ca 2+信号与 收缩激活目的4：确定其他因素的重要性 调节信号通路。丝裂原激活的蛋白激酶C 将测量蛋白激酶、钙调蛋白磷酸化级联。这 aim将决定是否失去维持的收缩力， 失代偿性膀胱是由于改变步骤重要的薄 灯丝调节这些研究的结果将阐明 兴奋-收缩偶联的特定步骤， 膀胱功能障碍此外，这些研究的结果将 也决定了收缩或调节蛋白的改变 与膀胱重塑有关， 了解负责的细胞和分子机制 与出口梗阻相关的膀胱功能低下。