Effect of [Cl(-)]i on ENaC activity from mouse cortical collecting duct cells.
Na(+) transport via epithelial Na(+) channel (ENaC) occurs across many epithelial surfaces and plays a key role in regulating salt and water absorption. In this study, we have examined the effects of cytosolic Na(+) and Cl(-) on ENaC activity by patch clamping single channel recording method in mouse cortical collecting duct cells (M1). Cytosolic Na(+) exerts its effect in change of ENaC open probability (Po). High cytosolic Na(+) significantly reduces ENaC Po. No change in channel conductance by cytosolic Na(+) is observed. However, decrease of cytosolic Cl(-) concentration significantly increases channel conductance and ENaC Po. This effect is due to the right shift of ENaC I-V curve to positive membrane potential. The virtue of ENaC conductance remains the same. Cl(-) channels like CFTR and VRAC are unlikely to be involved in this regulation. The results suggest that cytosolic Cl(-) could serve as a mediator to regulate ENaC activity, in accordance with the activities of Cl(-) channels.
Gu
Yuchun
Y
Department of Physiology, University of Birmingham, Birmingham, Edgbaston, UK. y.gu@bham.ac.uk
D000818:Animals; D002460:Cell Line; D002712:Chlorides / Q000378:metabolism*; D053503:Epithelial Sodium Channels / Q000235:genetics / Q000378:metabolism*; D015640:Ion Channel Gating; D007685:Kidney Tubules, Collecting / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D018408:Patch-Clamp Techniques; D012964:Sodium / Q000378:metabolism*
D002712:Chlorides; D053503:Epithelial Sodium Channels; D012964:Sodium