Sidhaye et al. (2006) observed a dose-responsive decrease in Aqp5 abundance in mouse lung epithelial cells exposed to hypotonic medium. Hypotonic reduction of AQP5 was augmented and reduced, respectively, by conditions that activated or inhibited Trpv4 (605427). Hypotonic reduction of AQP5 required extracellular calcium and was associated with increased intracellular calcium. The response to hypotonicity was recapitulated by coexpression of TRPV4 and AQP5 in human embryonic kidney cells.

Sidhaye et al. (2006) concluded that AQP5 abundance is tightly controlled along a spectrum of extracellular osmolalities and that its abundance in hypotonic conditions can be regulated by TRPV4 activation.