Expression of H(+)-ATPase in Inner Medullary Collecting Duct Cells of Aquaporin-3-Deficient Mice.
- Author:
Eun Jung LEE
1
;
Wan Young KIM
;
Ki Hwan HAN
;
Hyang KIM
;
Jin KIM
Author Information
1. Internal Medicine, Sungkyunkwan University, Korea.
- Publication Type:Original Article
- Keywords:
AQP3 knock-out mouse;
IMCD cell;
H(+)-ATPase;
NHE3
- MeSH:
Animals;
Cell Membrane;
Hydrogen-Ion Concentration;
Immunohistochemistry;
Kidney;
Loop of Henle;
Mice*;
Osmolar Concentration;
Proton-Translocating ATPases*;
Up-Regulation
- From:Korean Journal of Anatomy
2003;36(5):443-455
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
It has been reported that the decrease in urinary pH observed in AQP1 null mice with a urinary concentrating defect is due to upregulation of H(+)-ATPase in the IMCD. This is thought to be caused by the chronically low interstitial osmolality in these animals. To explore whether increase of H(+)-ATPase expression in the IMCD is associated with changes in the prolonged decrease of interstitial osmolality, we examined the expression of H(+)-ATPase and Na(+)-H(+) exchanger (NHE3) using light and electron microscopic immunocytochemistry in the kidneys of AQP3 null mice which are polyuric and manifest a urinary concentrating defect because of an inability to create a hypertonic medullary interstitium. In both AQP3 (-/-) and AQP1 (-/-) mouse kidneys, type A intercalated cells in cortical and medullary collecting ducts are slightly activated, and strong H(+)-ATPase immunostaining was present in the apical plasma membrane of IMCD cells, whereas no H(+)-ATPase labeling was observed in IMCD cells in wild type mice. No differences of the immunoreactivity for NHE3 in the proximal tubule and thick ascending limb of loop of Henle were observed between AQP3 or AQP1 (-/-) mice and AQP3 (+/+) mouse. These results suggest that the induction of H(+)-ATPase expression in IMCD cells of AQP3 null mice, as well as AQP1 null mice, may be related to their chronically low interstitial osmolality.
