Aquaporin-1 passively transports water out of cell

Aquaporin-1 (AQP1) passively transports water across the plasma membrane according to the osmotic gradient. In the kidney AQP1 is expressed in endothelial cells of the vasa recta, the proximal tubule, and thin descending limb of Henle, where it functions to recover water from filtrate during urine formation. AQP1 is expressed in many other tissues, such as red blood cells, pancreas, and choroid plexus. AQP1 plays a role in forming cerebrospinal fluid.

水通道蛋白-1（AQP1）根据渗透压梯度被动地跨越质膜运输水分。在肾脏中，AQP1在直血管内皮细胞、近端肾小管以及亨氏薄降支中表达，其在尿液形成过程中负责从滤液中回收水分。AQP1亦在其他多种组织中表达，如红细胞、胰腺和脉络丛。AQP1在形成脑脊液的过程中扮演着重要角色。