Characterization of two mammalian cortical collecting duct cell lines with hopping probe ion conductance microscopy.

We morphologically and physiologically characterized Madin-Darby canine kidney (MDCK) cell and mouse principal cell of kidney in cortical collecting duct (mpkCCD) via hopping probe ion conductance microscopy, transepithelial electrical resistance (TEER) measurements, and single-channel recordings. The specific membrane structures of microvilli and tight junctions were clearly observed in MDCK and mpkCCD cell monolayers. The electrophysiological functions of epithelial Na(+) channel in MDCK and mpkCCD cells were further characterized by measuring amiloride-sensitive TEER values for the whole-cell monolayer and detecting the ion channel activities with patch clamping. Our results provide more morphological and functional information to help better utilize these two mammalian CCD cell lines for mechanism studies of sodium absorption and reabsorption in the distal nephron.