ATP is released from rabbit urinary bladder epithelial cells by hydrostatic pressure changes - a possible sensory mechanism?
ATP is released from rabbit urinary bladder epithelial cells by hydrostatic pressure changes - a possible sensory mechanism?
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DOI：
10.1111/j.1469-7793.1997.503bb.x
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发表时间：
1997-12-01
影响因子：
5.5
通讯作者：
Burton, TJ
中科院分区：
文献类型：
--
作者：
Ferguson, DR;Kennedy, I;Burton, TJ
1.用Ussing小室和灌流仪研究了兔膀胱对静水压力变化和电刺激的反应。这些实验使我们能够监测跨组织的离子传输和细胞内ATP释放的变化。兔的膀胱壁上维持着电位差，这主要是由于钠从尿液(粘膜)到浆膜表面的主动转运。从组织一侧去除洗浴液产生的微小静水压差引起电位差和短路电流的可重复变化，这些变化的幅度随着去除的液体的体积的增加而增加。阿米洛利作用于粘膜(尿液)而不是浆膜表面，可降低跨上皮电位差和短路电流，其IC50为300纳米。4.阿米洛利可减少由静水压力改变引起的跨上皮电位改变，但不能消除这种改变。对膀胱组织条的场电刺激可产生可重复释放的三磷酸腺苷。这种释放主要发生在尿路上皮细胞中，在无钙的情况下，这种释放明显是非囊泡性的，而且不能被河豚毒素消除。有人认为，ATP是从尿路上皮释放出来的，作为兔膀胱扩张程度和其他感觉方式的感觉中介。
1. The responses of rabbit urinary bladder to hydrostatic pressure changes and to electrical stimulation have been investigated using both the Ussing chamber and a superfusion apparatus. These experiments enabled us to monitor changes in both ionic transport across the tissue and cellular ATP release from it.2. The urinary bladder of the rabbit maintains an electrical potential difference across its wall as a result largely of active sodium transport from the urinary (mucosal) to the serosal surface.3. Small hydrostatic pressure differences produced by removal of bathing fluid from one side of the tissue caused reproducible changes in both potential difference and short-circuit current, The magnitude of these changes increases as the volume of fluid removed increases.3. Amiloride on the mucosal (urinary), but not the serosal, surface of the membrane reduces the transepithelial potential difference and short-circuit current with an IC50 of 300 nM. Amiloride reduces the size of, but does not abolish, transepithelial potential changes caused by alterations in hydrostatic pressure.4. Field electrical stimulation of strips of bladder tissue produces a reproducible release of ATP. Such release was demonstrated to occur largely from urothelial cells and is apparently nonvesicular as it increases in the absence of calcium and is not abolished by tetrodotoxin.5. It is proposed that ATP is released from the urothelium as a sensory mediator for the degree of distension of the rabbit urinary bladder and other sensory modalities.