Ksiazek Krzysztof, Witowski Janusz
Katedra i Zakład Patofizjologii Akademii Medycznej, 60-781 Poznań, ul. Swiecickiego 6.
Przegl Lek. 2002;59(12):1013-7.
The aquaporins (AQP) are a family of small transmembrane water channels. The discovery of AQP has provided insight into molecular mechanisms underlying renal water absorption and its regulation by vasopressin. Seven types of AQP have been identified in the kidney. AQP1 has been localized in the proximal tubule and descending thin limb, while AQP2, AQP3, and AQP4 are expressed in the collecting duct. Of these isoforms, AQP2 expression and intracellular trafficking is tightly regulated by vasopressin. Decreased expression of renal AQP has been detected in several disorders associated with polyuria and impaired ability to concentrate urine, as exemplified by nephrogenic diabetes insipidus or renal failure. In contrast, increased expression of AQP is seen in conditions leading to water retention, such as congestive heart failure, liver cirrhosis, and syndrome of inappropriate antidiuretic hormone secretion. Thus, the understanding of molecular structure and function of aquaporins may have important implications for therapy of water balance disorders.
水通道蛋白（AQP）是一类小的跨膜水通道家族。水通道蛋白的发现为肾水重吸收及其受血管加压素调节的分子机制提供了深入了解。已在肾脏中鉴定出七种类型的水通道蛋白。水通道蛋白1定位于近端小管和降支细段，而水通道蛋白2、水通道蛋白3和水通道蛋白4在集合管中表达。在这些异构体中，水通道蛋白2的表达和细胞内运输受到血管加压素的严格调节。在几种与多尿和尿液浓缩能力受损相关的疾病中，如肾性尿崩症或肾衰竭，已检测到肾水通道蛋白表达降低。相反，在导致水潴留的情况下，如水钠潴留，如充血性心力衰竭、肝硬化和抗利尿激素分泌不当综合征，可见水通道蛋白表达增加。因此，对水通道蛋白分子结构和功能的了解可能对水代谢紊乱的治疗具有重要意义。
