Ion Channels in the Mammalian Nephron

Abstract

After the initial description of ion channels by patch clamp analysis in cultured cell lines derived from renal epithelia some 7 years ago, much progress has been made in the application of this technique to primary cultures of renal cells of defined origin, and to intact and even to in vitro perfused renal tubules. The present brief overview will focus mostly on data derived from intact tubules; the emphasis will be on the most recent data on ion channel regulation. Comparison to data obtained from cultured cells reveals that there are distinct differences between various preparations. Furthermore, in patch clamp experiments, several types of ion channels have been found which are probably not relevant for the normal function of the intact tubule cell. Conversely, some of the conductance properties of the intact cell are not recovered by corresponding ion channels in patch clamp experiments. Much further work and new methods will be required to reconstitute the conductance properties of the intact tubule from the findings in single ion channels.