Abstract
The volume-sensitive outwardly rectifying (VSOR) chloride channel is ubiquitously expressed and involved in cell volume regulation after osmotic swelling in various cell types. In adipose cells, we previously found that a preadipose cell line 3T3-L1 expresses functional VSOR channels. Here, by using a whole-cell patch-clamp technique, we examined whether or not the VSOR channel is expressed in white adipocytes acutely isolated from mice epididymal fat pads. Whole-cell voltage-clamp recordings revealed that chloride currents were gradually activated upon cell swelling induced by application of hypotonic solution. This current was inhibited by a chloride channel blocker, NPPB, or hypertonic solution, and showed outward rectification and inactivation kinetics at large positive potentials. These electrophysiological and pharmacological properties are consistent with those of the VSOR channel in other cell types. It is concluded that the VSOR channel is functionally expressed in white adipocytes acutely isolated from mice. [J Physiol Sci. 2008;58 Suppl:S208]
