Related Experiment Video
Updated: Jul 19, 2026

Reconstruction of the Blood-Brain Barrier In Vitro to Model and Therapeutically Target Neurological Disease
Published on: October 20, 2023
UT-B1 urea transporter plays a noble role as active water transporter in C6 glial cells
Aya Ogami1, Hiroaki Miyazaki, Naomi Niisato
1Department of Molecular Cell Physiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602 8566, Japan.
Abstract:
Since our experimental results suggest that UT-B1 functions as active water transporter against osmotic gradient in C6 glial cells, we report here for the first time the evidence for the active water transport. Exposure of C6 cells to a hyperosmotic solution containing glycerol or sucrose produced cell shrinkage due to water efflux according to osmotic gradient for water movement. On the other hand, C6 cells show cell swelling against osmotic gradient for water movement just after exposure to a hyperosmotic solution containing urea, indicating that water influx against osmotic gradient for water movement is accelerated by urea; i.e., urea performs active water transport. A specific inhibitor of UT-B, pCMBS, blocked the urea-induced swelling. The urea-induced cell swelling was significantly suppressed in the siRNA-induced UT-B1-knockdown C6 cells. Taken together, these observations indicate that UT-B1 acts as an active water transporter, providing a new model on active water transport.
Related Concept Videos
Transcellular Transport of Solutes
Active Transport
Primary active transporters, like Na+, K+ and -ATPase, directly utilize ATP to move ions across the membrane. These transporters play significant roles in various physiological processes. For instance, Na+, K+ and -ATPase maintain...
Carrier-Mediated Transport
Active transport involves two types of membrane-spanning transporters: uptake and efflux. Uptake transporters are expressed in the small...
The Blood-brain Barrier
Secondary Active Transport
Secondary Active Transport

