Novel Schering and ouabain-insensitive potassium-dependent proton secretion in the mouse cortical collecting duct

The intercalated (IC) cells of the cortical collecting duct (CCD) are important to acid-base homeostasis by secreting acid and reabsorbing bicarbonate. Acid secretion is mediated predominantly by apical membrane Schering (SCH-28080)-sensitive H(+)-K(+)- ATPase (HKA) and bafilomycin-sensitive H(+)-AT...

Full description

Saved in:
Bibliographic Details
Published in:American journal of physiology. Renal physiology 2002-01, Vol.282 (1), p.F133-F143
Main Authors: Petrovic, Snezana, Spicer, Zachary, Greeley, Tracey, Shull, Gary E, Soleimani, Manoocher
Format: Article
Language:English
Subjects:
Acid-Base Equilibrium - drug effects
Acid-Base Equilibrium - physiology
Animals
Blotting, Northern
Carrier Proteins - metabolism
Enzyme Inhibitors - pharmacology
H(+)-K(+)-Exchanging ATPase - genetics
H(+)-K(+)-Exchanging ATPase - metabolism
Hydrogen-Ion Concentration
Imidazoles - pharmacology
Kidney Cortex - metabolism
Kidney Cortex - secretion
Kidney Tubules, Collecting - metabolism
Kidney Tubules, Collecting - secretion
Mice
Mice, Knockout
Ouabain - pharmacology
Potassium - metabolism
Protons
Reverse Transcriptase Polymerase Chain Reaction
RNA, Messenger - analysis
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The intercalated (IC) cells of the cortical collecting duct (CCD) are important to acid-base homeostasis by secreting acid and reabsorbing bicarbonate. Acid secretion is mediated predominantly by apical membrane Schering (SCH-28080)-sensitive H(+)-K(+)- ATPase (HKA) and bafilomycin-sensitive H(+)-ATPase. The SCH-28080-sensitive HKA is believed to be the gastric HKA (HKAg). Here we examined apical membrane potassium-dependent proton secretion in IC cells of wild-type HKAg (+/+) and HKAg knockout (-/-) mice to determine relative contribution of HKAg to luminal proton secretion. The results demonstrated that HKAg (-/-) and wild-type mice had comparable rates of potassium-dependent proton secretion, with HKAg (-/-) mice having 100% of K(+)-dependent H(+) secretion vs. wild-type mice. Potassium-dependent proton secretion was resistant to ouabain and SCH-28080 in HKAg knockout mice but was sensitive to SCH-28080 in wild-type animals. Northern hybridizations did not demonstrate any upregulation of colonic HKA in HKAg knockout mice. These data indicate the presence of a previously unrecognized K(+)-dependent SCH-28080 and ouabain-insensitive proton secretory mechanism in the cortical collecting tubule that may play an important role in acid-base homeostasis.
ISSN:1931-857X
1522-1466
DOI:10.1152/ajprenal.0124.2001