OBSTRUCTION INDUCED CHANGES IN URINARY BLADDER MUSCLE

描述(改编自申请人的摘要)：妨碍 尿路导致膀胱的许多变化， 损害了它的存储和清空特性。详细的分子 负责这些功能变化的机制与 梗阻引起的重塑尚未被清楚地描绘出来。这 研究项目基于这样一种假设，即抑郁症 梗阻性膀胱的功能是两者改变的结果。 兴奋-收缩偶联(钙可利用性)与收缩 逼尿肌中的钙依赖活动。为了测试这一点 假设，下面的具体目标将使用条带来实现 从正常、失代偿和代偿的逼尿肌中获得 兔子的膀胱。目标1：关联力-速度-长度关系 与膀胱相关的完整和带皮的逼尿肌 障碍物及其逆转。这一目标将决定 改变了组织、细胞和交叉处的主动和被动力学- 驾驶台水平。经过化学处理的肌肉条将允许 对周围环境的精确和直接控制 收缩装置，绕过正常的兴奋-收缩 路径。目的2：确定激动剂之间的关系 浓度、胞浆(Ca~(2+))和收缩时间。 笼状化合物的激光光解将被用来引发收缩 同时用INDO-1监测细胞内钙离子浓度。这一目标将 确定收缩能力改变是否是由于钙离子改变 动员。目的3：测定肌球蛋白轻链的时间进程 完整光和肌球蛋白光的磷酸化、钙离子和等长力 链磷酸化、肌动蛋白激活的肌球蛋白ATPase活性和 不同刺激条件下通透性组织中的等长力。这 AIM将测试Ca~(2+)信号与 收缩激活。目标4：确定其他因素的重要性 调节信号通路。有丝分裂原激活的蛋白激酶C 将测定蛋白激酶、钙调蛋白磷酸化级联反应。这 AIM将确定维持的收缩力的损失是否 膀胱失代偿是由于瘦的重要步骤的改变所致 灯丝调节。这些研究的结果将阐明 兴奋-收缩耦合的具体步骤 伴有膀胱功能障碍。此外，这些研究的结果将 还可以确定收缩或调节蛋白的哪些变化 与膀胱重塑有关，并将提供更完整的 对细胞和分子机制的理解 与出口梗阻相关的膀胱功能低落。

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.