Figure 11

Schematic model for the multiple mechanisms of CCB-inhibited transepithelial Na⁺transport and recovery by K⁺channels. CCB compounds alter Ca²⁺ signal most likely via modifying Ca²⁺ release from cytosolic compartments. In addition, CCB compounds directly regulate K⁺ channels, ENaC, and Na⁺/K⁺-ATPase. Disrupted basolateral K⁺ recycling and apical ion transport will abrogate transalveolar salt and fluid transport. K⁺ channel openers significantly restore the CCB-inhibited transepithelial Na⁺ transport by activating K⁺ channel, then facilitating Na⁺/K⁺-ATPase.