Expression, localization, and regulation of aquaporin-1 to-3 in rat urothelia
Expression, localization, and regulation of aquaporin-1 to-3 in rat urothelia
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DOI：
10.1152/ajprenal.00136.2001
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发表时间：
2002-06-01
影响因子：
4.2
通讯作者：
Weinman, EJ
中科院分区：
文献类型：
--
作者：
Spector, DA;Wade, JB;Weinman, EJ
虽然哺乳动物尿路上皮通常被认为不能渗透尿液成分，但对几个物种的体内研究表明，尿路上皮在某些条件下可以运输水和溶质。本研究调查了 48 小时脱水和水负荷雌性 Wistar 大鼠输尿管和膀胱组织中水通道蛋白 (AQP)-1、-2 和 -3 的表达、定位和调节。整个输尿管和膀胱匀浆的免疫印迹鉴定出与 AQP-1、-2 和 -3 的 28- 和 35- 至 44-kDa 条带相似的特征。 AQP-1 定位于毛细血管和小动脉内皮细胞，而 AQP-2 和 -3 则沿上皮细胞膜周向排列，除了邻近输尿管和膀胱管腔的上皮细胞的顶膜外。 AQP-2 也存在于上皮细胞的细胞质中。脱水导致输尿管和膀胱匀浆免疫印迹上的 AQP-3 信号增加 160-200%，AQP-2 信号增加 24-49%，但 AQP-1 信号没有变化。泌尿生殖道尿路上皮中的 AQP 可能在上皮细胞体积和渗透压的调节中发挥作用，并且可能在穿过尿路上皮的大量水运动中发挥作用。
Although mammalian urothelia are generally considered impermeable to constituents of urine, in vivo studies in several species indicate urothelial transport of water and solutes under certain conditions. This study investigates the expression, localization, and regulation of aquaporin (AQP)-1, -2, and -3 in ureteral and bladder tissues in 48-h dehydrated and water-loaded female Wistar rats. Immunoblots of homogenates of whole ureter and bladder identified characteristic similar to28- and 35- to 44-kDa bands for AQP-1, -2, and -3. AQP-1 was localized to capillary and arteriole endothelial cells, whereas AQP-2 and -3 circumferentially lined the epithelial cell membranes except for the apical membrane of the epithelial cells adjacent to the lumens of both ureter and bladder. AQP-2 was also present in epithelial cell cytoplasm. Dehydration resulted in 160-200% increases of AQP-3 signal and 24-49% increases of AQP-2 signal but no change in AQP-1 signal on immunoblots of homogenates of ureters and bladders. AQPs in genitourinary tract urothelia likely play a role in the regulation of epithelial cell volume and osmolality and may play a role in bulk water movement across urothelia.