TRPV4 and edema: TRPV4 also plays an important role in the formation of pulmonary edema and acute lung injury.378,419 TRPV4 agonists caused pulmonary endothelial permeability, which was inhibited by the non-selective TRP blocker ruthenium red and was absent in Trpv4 knockout mice.420 Evidence showing that activation of TRPV4 may be involved in disrupting the integrity of the epithelial and endothelial barriers suggests the possible role of TRPV4 in edema formation.