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

这个项目旨在研究特定的兴奋-收缩耦合 在分离的膀胱平滑肌细胞中的机制，并确定是否 这些过程与收缩功能障碍有关 患有慢性膀胱梗阻两个重要的耦合 将检查与这种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，可能是钙离子 将使用同步单细胞膜片钳技术鉴定渗透物 方法和Fura 2钙测量。ATP作用于嘌呤能 受体在膀胱功能中起重要作用。配体- 门控阳离子通道介导膀胱嘌呤能兴奋电流 平滑肌细胞将被识别并与这些特性相关联 最近克隆的P2 X受体/通道。钙渗透， 这些通道的生物物理和药理学特性在兔 逼尿肌将被确定。CICR似乎是一个重要组成部分， 膀胱肌细胞的兴奋/收缩偶联。的能力 钙电流和阳离子电流释放钙， 肌浆网将使用同时测量来确定 细胞内钙和电流的电压钳位心肌细胞。的 还将测定P2 X基因的表达。这些过程将 与正常、失代偿和逆转的细胞相比， 膀胱，以确定非选择性阳离子通道的作用 和CICR在梗阻后膀胱功能障碍中的作用。在多大程度 CICR、非选择性阳离子通道或下游钙离子通道 失代偿膀胱中的释放/摄取过程发生改变， 光的过程中潜在的膀胱功能障碍与 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.