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

通道蛋白的表达

• 批准号: 6201933
• 负责人: Michael I. Kotlikoff
• 金额: $ 18.13万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-09-01 至 2000-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6201933
• 关键词: acetylcholine; adenosine triphosphate; animal tissue; calcium channel; calcium flux; calcium ion; calcium transporting ATPase; cations; electrophysiology; fluorescent dye /probe; gene expression; human tissue; membrane channels; muscarinic receptor; muscle cells; muscle contraction; polymerase chain reaction; purinergic receptor; single cell analysis; smooth muscle; urinary bladder; urinary bladder disorder; urination disorder; voltage /patch clamp

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.

该项目旨在研究特定的兴奋-收缩耦合 分离的膀胱平滑肌细胞的机制，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 将检查与此功能障碍有关的过程： 非选择性阳离子通道和钙诱导钙释放（CICR）。 由神经递质激活的阳离子通道，可能是钙 将使用同时单细胞、膜片钳来鉴定渗透物 方法和 Fura 2 钙测量。 ATP作用于嘌呤能 受体在膀胱功能中起着重要作用。配体- 介导膀胱嘌呤能兴奋电流的门控阳离子通道 平滑肌细胞将被识别并与特性相关联 最近克隆的 P2X 受体/通道。钙渗透， 兔体内这些通道的生物物理和药理学特性 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/收缩耦合。能力 钙电流和阳离子电流的结合以释放钙 肌浆网将通过同时测量来确定 电压钳位肌细胞中细胞内钙和电流的变化。这 P2X 基因的表达也将被确定。这些过程将 与正常细胞、失代偿细胞和逆转细胞分离的细胞进行比较 膀胱确定非选择性阳离子通道的作用 和 CICR 治疗梗阻性膀胱功能障碍。程度到 CICR、非选择性阳离子通道或下游钙 失代偿性膀胱的释放/摄取过程发生改变，膀胱会脱落 阐明与膀胱功能障碍相关的潜在过程 尿流梗阻。