Phosphoinositide 3-kinase pathway mediates early aldosterone action on morphology and epithelial sodium channel in mammalian renal epithelia.

Involvement of phosphoinositide 3-kinases (PI3Ks) in early aldosterone action on epithelial sodium channel (ENaC) in mammalian renal epithelia was investigated by hopping probe ion conductance microscopy combined with patch-clamping in this study. Aldosterone treatment enlarged the cell volume and elevated the apical membrane of renal mpkCCDc14 epithelia, which resulted in enhancing the open probability of ENaC. Inhibition of PI3K pathway by LY294002 obviously suppressed these aldosterone-induced changes in both cell morphology and ENaC activity. These results indicated the important role of PI3K pathway in early aldosterone action and the close relationship between cell morphology and ENaC activity in mammalian renal epithelia.