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Late in gestation lung epithelium changes from net chloride and fluid secretion to sodium and fluid absorption. Fluid resorption is required for postnatal gas exchange and occurs by combined action of epithelial sodium channels and Na, K-ATPase. We hypothesized that alveolar epithelial Na, K-ATPase increases perinatally. Immunofluorescence (IF) and immunoelectron microscopy (IEM) with a monoclonal anti-alpha subunit antibody demonstrated that Na, K-ATPase was present on the basolateral surfaces of columnar epithelial cells at fetal day (FD) 17 and on type II cells throughout development. However, type I epithelial cells did not have detectable Na,K-ATPase. The steady-state levels of both the alpha 1 isoform and the beta-subunit mRNAs were maximal at FD20-neonatal day (ND) 1, with consistent increases from FD17 level. Na, K-ATPase alpha-subunit protein also increased from FD17 to FD20-22 and then decreased in the early postnatal period. The ouabain-inhibitable sodium pump activity per milligram membrane protein increased 2.6-fold from FD17 to FD22-ND1 (P < 0.05). The quantities of sodium pump mRNA, antigenic protein, and enzyme activity increase in late gestation in accord with a proposed role for Na, K-ATPase in resorption of alveolar sodium and fluid in preparation for birth.
D H Ingbar, and
C B Weeks, and
M Gilmore-Hebert, and
E Jacobsen, and
S Duvick, and
R Dowin, and
S K Savik, and
J D Jamieson
March 2001,
Cellular and molecular biology (Noisy-le-Grand, France),
D H Ingbar, and
C B Weeks, and
M Gilmore-Hebert, and
E Jacobsen, and
S Duvick, and
R Dowin, and
S K Savik, and
J D Jamieson
December 1990,
The American journal of physiology,
D H Ingbar, and
C B Weeks, and
M Gilmore-Hebert, and
E Jacobsen, and
S Duvick, and
R Dowin, and
S K Savik, and
J D Jamieson
April 1997,
The American journal of physiology,
D H Ingbar, and
C B Weeks, and
M Gilmore-Hebert, and
E Jacobsen, and
S Duvick, and
R Dowin, and
S K Savik, and
J D Jamieson
December 2007,
Journal of bioenergetics and biomembranes,
D H Ingbar, and
C B Weeks, and
M Gilmore-Hebert, and
E Jacobsen, and
S Duvick, and
R Dowin, and
S K Savik, and
J D Jamieson
March 1996,
The European respiratory journal,
D H Ingbar, and
C B Weeks, and
M Gilmore-Hebert, and
E Jacobsen, and
S Duvick, and
R Dowin, and
S K Savik, and
J D Jamieson
December 2008,
Fundamental & clinical pharmacology,
D H Ingbar, and
C B Weeks, and
M Gilmore-Hebert, and
E Jacobsen, and
S Duvick, and
R Dowin, and
S K Savik, and
J D Jamieson
February 2010,
Proceedings of the American Thoracic Society,
D H Ingbar, and
C B Weeks, and
M Gilmore-Hebert, and
E Jacobsen, and
S Duvick, and
R Dowin, and
S K Savik, and
J D Jamieson
January 1988,
Progress in clinical and biological research,
D H Ingbar, and
C B Weeks, and
M Gilmore-Hebert, and
E Jacobsen, and
S Duvick, and
R Dowin, and
S K Savik, and
J D Jamieson
September 1993,
Current opinion in nephrology and hypertension,
D H Ingbar, and
C B Weeks, and
M Gilmore-Hebert, and
E Jacobsen, and
S Duvick, and
R Dowin, and
S K Savik, and
J D Jamieson
July 1988,
Biochimica et biophysica acta,
