title: Electrochemical forces for chloride transport in the proximal tubules of the rat kidney.
abstract: The electrochemical forces for chloride transport in the proximal tubule of the rat kidney were studied using micropuncture techniques. Electrical transmembrane potentials were recorded in randomly punctured tubules with Ling-Gerhard electrodes. Chloride activities in the luminal, cellular and interstitial compartments were measured with ion selective micro-electrodes. Electrical potential measurements between cell to interstitium and lumen to interstitium were -72.1 +/- 2.6 mV and +0.5 +/- 1.4 mV (mean +/- S.D.) respectively. The calculated chloride concentrations for lumen, cell and interstitium were 133.0 +/- 10.3 mM, 8.5 +/- 1.0 mM and 99.1 +/- 3.2 mM (mean +/- S.D.) respectively. The net electrochemical forces, qualitatively, offer a passive chloride ion pathway through the tubular wall and a chloride equilibrium over the luminal membrane seems to exist.
mesh_terms: D000818:Animals; D002712:Chlorides / Q000502:physiology*; D004563:Electrochemistry; D007687:Kidney Tubules, Proximal / Q000502:physiology*; D008564:Membrane Potentials; D008839:Microelectrodes; D051381:Rats
chemical_list: D002712:Chlorides