Novel regulation of cell [Na(+)] in macula densa cells: apical Na(+) recycling by H-K-ATPase.

Content Provider	Semantic Scholar
Author	Peti-Peterdi, János Bebők, Zsuzsa Lapointe, Jean-Yves Bell, Phillip Darwin
Copyright Year	2002
Abstract	Na-K-ATPase is the nearly ubiquitous enzyme that maintains low-Na(+), high-K(+) concentrations in cells by actively extruding Na(+) in exchange for K(+). The prevailing paradigm in polarized absorbing epithelial cells, including renal nephron segments and intestine, has been that Na-K-ATPase is restricted to the basolateral membrane domain, where it plays a prominent role in Na(+) absorption. We have found, however, that macula densa (MD) cells lack functionally and immunologically detectable amounts of Na-K-ATPase protein. In fact, these cells appear to regulate their cytosolic [Na(+)] via another member of the P-type ATPase family, the colonic form of H-K-ATPase, which is located at the apical membrane in these cells. We now report that this constitutively expressed apical MD colonic H-K-ATPase can function as a Na(H)-K-ATPase and regulate cytosolic [Na(+)] in a novel manner. This apical Na(+)-recycling mechanism may be important as part of the sensor function of MD cells and represents a new paradigm in cell [Na(+)] regulation.
File Format	PDF HTM / HTML
DOI	10.1152/ajprenal.00251.2001
PubMed reference number	11788447
Journal	Medline
Volume Number	282
Issue Number	2
Alternate Webpage(s)	http://ajprenal.physiology.org/content/ajprenal/282/2/F324.full.pdf
Alternate Webpage(s)	https://doi.org/10.1152/ajprenal.00251.2001
Journal	American journal of physiology. Renal physiology
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article