ACTIVATION OF A CL- CONDUCTIVE PATHWAY IN PRIMARY CULTURES OF RAT INNER MEDULLARY COLLECTING DUCT (IMCD) CELLS UNDER HYPOTONIC STRESS

In intracellular recordings with conventional microelectrodes on rat I MCD cells, we find that hypotonic stress depolarizes membrane voltage and decreases cell input resistance. Ion substitution experiments reve al that these effects are largely due to the activation of a prominent Cl- conductance. After block of this conductance with dideoxyforskoli n a smaller concomitant increase in K+ conductance becomes detectable.