Skip to main content
. Author manuscript; available in PMC: 2013 Mar 1.
Published in final edited form as: Int J Biochem Cell Biol. 2011 Dec 13;44(3):431–434. doi: 10.1016/j.biocel.2011.12.002

Figure 1.

Figure 1

Transport model of the principal and mitochondria-rich cells of the frog skin epithelium. Na+ is moved from the pond solution via epithelial Na+ channels (ENaC) in the apical membrane and extruded via the Na+/K+ ATPase in the basolateral membrane. Excess cytosolic K+ generated by activity of the Na+/K+ ATPase is recycled to the plasma via K+ channels in the basolateral membrane. The transepithelial potential difference generated by this mechanism drives absorption of Cl− through mitochondria-rich cells and through paracellular pathways. NaCl absorption generates an osmotic gradient that drives absorption of water via aquaporin channels (AQP).