Feline interstitial cystitis results in mechanical hypersensitivity and altered ATP release from bladder urothelium
Feline interstitial cystitis results in mechanical hypersensitivity and altered ATP release from bladder urothelium
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DOI：
10.1152/ajprenal.00056.2003
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发表时间：
2003-09-01
影响因子：
4.2
通讯作者：
Buffington, CA
中科院分区：
文献类型：
--
作者：
Birder, LA;Barrick, SR;Buffington, CA
ATP可以通过机械刺激从多种细胞类型中释放;然而，这种释放的机制和病理学的影响还不清楚。本研究检查了正常猫和诊断为间质性膀胱炎（猫间质性膀胱炎; FIC）的猫尿路上皮细胞中肿胀诱发（暴露于低渗溶液）ATP释放的细胞内信号传导机制。使用荧光素酶生物发光测定，我们证明，肿胀诱发的ATP释放显着升高FIC细胞。在正常和FIC细胞中，ATP释放显着降低（平均70%的下降）的应用程序的阻断剂的拉伸激活通道（阿米洛利或钆），以及布雷菲德菌素A和莫能菌素（平均90%的下降），这表明ATP释放时，发生含ATP的囊泡与质膜融合。去除外部钙后，肿胀诱发的释放减少（65%），释放被阻断与BAPTA-AM或干扰内部钙储存剂（咖啡因，兰尼定，肝素，或2-氨基乙氧基二苯基硼酸盐）孵育。此外，已知通过肌醇1，4，5-三磷酸（IP（3））受体（毒胡萝卜素，乙酰胆碱）发挥作用的药物在FIC中释放的ATP明显多于正常尿路上皮。综上所述，这些结果表明，FIC导致一种新的对机械刺激的超敏反应，可能涉及IP（3）敏感通路的改变。
ATP can be released from a variety of cell types by mechanical stimulation; however, the mechanism for this release and the influence of pathology are not well understood. The present study examined intracellular signaling mechanisms involved in swelling-evoked (exposure to a hypotonic solution) release of ATP in urothelial cells from normal cats and cats diagnosed with interstitial cystitis (feline interstitial cystitis; FIC). Using the luciferin-luciferase bioluminescent assay, we demonstrate that swelling-evoked ATP release is significantly elevated in FIC cells. In both normal and FIC cells, ATP release was significantly decreased (mean 70% decrease) by application of blockers of stretch-activated channels (amiloride or gadolinium), as well as brefeldin A and monensin (mean 90% decrease), suggesting that ATP release occurs when ATP-containing vesicles fuse with the plasma membrane. Swelling-evoked release was reduced after removal of external calcium (65%), and release was blocked by incubation with BAPTA-AM or agents that interfere with internal calcium stores (caffeine, ryanodine, heparin, or 2-aminoethoxydiphenyl borate). In addition, agents known to act through inositol 1,4,5-triphosphate (IP(3)) receptors (thapsigargin, acetylcholine) release significantly more ATP in FIC compared with normal urothelium. Taken together, these results suggest that FIC results in a novel hypersensitivity to mechanical stimuli that may involve alterations in IP(3)-sensitive pathways.