The control of Na ⁺-H⁺3 exchange in epithelial cells
H Ishibashi, M Cummings, DI Cook, P Poronnik
collaborator: CA Pollock, Dept of Medicine

We are currently investigating the mechanisms of control of Na ⁺-H⁺ exchange in two epithelia: (i) salivary endpiece cells and (ii) cultured human proximal tubule cells. In salivary endpiece cells we are investigating the effects of intracellular mediators on the activity of the Na⁺-H⁺ exchanger. Thus far we have demonstrated that the dominant Na⁺-H⁺ exchange isoform in these cells is NHE1 and that the activity of this isoform requires the presence of ATP in the cytosol.

In 1997, a collaborative study looked at the effects of IGF-I on the activity of Na ⁺-H⁺ exchangers in cultured human proximal tubule cells.