EXPRESSION OF CHANNEL PROTEINS & CA PUMP--REMODELING BLADDER SMOOTH MUSCLE

这个项目试图研究特定的兴奋-收缩耦合。 在分离的膀胱平滑肌细胞中的机制，并确定 这些过程与相关的收缩功能障碍有关 患有慢性膀胱梗阻。两个重要的耦合 将检查与此功能障碍有关的过程： 非选择性阳离子通道和钙诱导的钙释放(CICR)。 由神经递质激活的阳离子通道，可能是钙 将使用同时的单细胞膜片钳来识别意指 方法和Fura-2钙测定。作用于嘌呤能的三磷酸腺苷 受体在膀胱功能中起着重要作用。配基- 门控阳离子通道介导膀胱嘌呤能兴奋电流 将对平滑肌细胞进行鉴定并将其与属性相关联 最近克隆的P2X受体/通道。钙离子的渗透， 这些通道在兔体内的生物物理和药理特性 逼尿肌将被确定。CICR似乎是一个重要的组成部分 膀胱肌细胞的兴奋/收缩偶联。一种能力 释放钙的钙电流和阳离子电流 将使用同步测量来确定肌浆网 电压钳制心肌细胞内钙离子和电流的变化。这个 还将确定P2X基因的表达情况。这些进程将是 比较从正常、失代偿和反转分离的细胞 确定非选择性阳离子通道在膀胱中的作用 CICR在梗阻后膀胱功能障碍中的作用。达到的程度 CICR、非选择性阳离子通道或下游钙离子 失代偿膀胱的释放/摄取过程发生改变 与膀胱功能障碍相关的潜在过程的概述 尿流出道梗阻。

This project seeks to examine specific excitation-contraction coupling mechanisms in isolated bladder smooth muscle cells, and to determine if these processes are associated with the contractile dysfunction associated with chronic obstruction of the urinary bladder. Two important coupling process that have been implicated in this dysfunction will be examined: non-selective cation channels and calcium-induced calcium release (CICR). Cation channels that are activated by neurotransmitters and may be calcium permeant will be identified using simultaneous single-cell, patch-clamp methods and fura 2 calcium measurements. ATP acting on purinergic receptors plays an important role in urinary bladder function. The ligand- gated cation channels mediating purinergic excitatory currents in bladder smooth muscle cells will be identified and correlated with the properties of recently cloned P2X receptor/channels. The calcium permeation, biophysical and pharmacological properties of these channels in rabbit detrusor will be determined. CICR appears to be an important component of excitation/contraction coupling in urinary bladder myocytes. The ability of calcium currents and cation currents to release calcium from sarcoplasmic reticulum will be determine using simultaneous measurements of intracellular calcium and current in voltage-clamped myocytes. The expression of P2X genes will also be determined. These processes will be compared in cells dissociated from normal, decompensated, and reversed urinary bladders to determine the role of non-selective cation channels and CICR in post obstructive urinary bladder dysfunction. The extent to which CICR, non-selective cation channels or downstream calcium release/uptake processes are altered in decompensated bladders will shed light on the processes underlying bladders dysfunction associated with urinary outflow obstruction.