Potassium and ANO1/ TMEM16A chloride channel profiles distinguish atypical and typical smooth muscle cells from interstitial cells in the mouse renal pelvis

In this study, we have recorded the electrical activity in single SMCs and interstitial cells (ICs) isolated after enzymatic dispersal of the mouse renal pelvis using standard whole-cell (at 22-C) or nystatin perforated-patch (at 37-C) voltage clamp techniques. Antibodies raised against the likely subunits of the K+ and Cl- channels identified were also applied to coronal sections of mouse kidney to determine the location of these cells in situ. In some experiments, we have used a transgenic mouse that has an enhanced yellow ?uorescent protein (eYFP) coupled to the promoter for the gene controlling a-smooth muscle actin (a-SMA) expression (Li et al., 2009) and established that two populations of eYFP-aSMA + cells could be distinguished on the basis of their ion channel profiles, while a-SMA- ICs were distinguished by the presence of a transient K+ current that was blocked by Xe991, a blocker of KV7 channel currents.