Fluid and solute reabsorption by the proximal tubule is the result of
both transcellular and paracellular flux. The role of transcellular tr
ansport has been extensively studied, bot the importance of paracellul
ar flux has not been as thoroughly investigated. The purpose of this r
eview is to update concepts about the contribution of paracellular tra
nsport for reabsorption by the proximal tubule.