Document Detail


Secretory state regulates Zn2+ transport in gastric parietal cell of the rabbit.
MedLine Citation:
PMID:  19675302     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Secretory compartments of neurons, endocrine cells, and exocrine glands are acidic and contain high levels of labile Zn2+. Previously, we reported evidence that acidity is regulated, in part, by the content of Zn2+ in the secretory [i.e., tubulovesicle (TV)] compartment of the acid-secreting gastric parietal cell. Here we report studies focusing on the mechanisms of Zn2+ transport by the TV compartment in the mammalian (rabbit) gastric parietal cell. Uptake of Zn2+ by isolated TV structures was monitored with a novel application of the fluorescent Zn2+ reporter N-(6-methoxy-8-quinolyl)-para-toluenesulfonamide (TSQ). Uptake was suppressed by removal of external ATP or blockade of H+-K+-ATPase that mediates luminal acid secretion. Uptake was diminished with dissipation of the proton gradient across the TV membrane, suggesting Zn2+/H+ antiport as the connection between Zn2+ uptake and acidity in the TV lumen. In isolated gastric glands loaded with the reporter fluozin-3, inhibition of H+-K+-ATPase arrested the flow of Zn(2+) from the cytoplasm to the TV compartment and secretory stimulation with forskolin enhanced vectorial movement of cytoplasmic Zn2+ into the tubulovesicle/lumen (TV/L) compartment. Our findings suggest that Zn2+ accumulation in the TV/L compartment is physiologically coupled to secretion of acid. These findings offer novel insight into mechanisms regulating Zn2+ homeostasis in the gastric parietal cell and potentially other cells in which acidic subcellular compartments serve signature functional roles.
Authors:
Haley B Naik; Melissa Beshire; Breda M Walsh; Jingjing Liu; David I Soybel
Publication Detail:
Type:  In Vitro; Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2009-08-12
Journal Detail:
Title:  American journal of physiology. Cell physiology     Volume:  297     ISSN:  1522-1563     ISO Abbreviation:  Am. J. Physiol., Cell Physiol.     Publication Date:  2009 Oct 
Date Detail:
Created Date:  2009-10-02     Completed Date:  2009-12-03     Revised Date:  2013-06-02    
Medline Journal Info:
Nlm Unique ID:  100901225     Medline TA:  Am J Physiol Cell Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  C979-89     Citation Subset:  IM    
Affiliation:
Department of Surgery, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.
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MeSH Terms
Descriptor/Qualifier:
Aminoquinolines
Animals
Cations, Divalent / metabolism
Fluorescent Dyes
H(+)-K(+)-Exchanging ATPase / metabolism*
Hydrogen-Ion Concentration
Ion Transport
Parietal Cells, Gastric / metabolism*,  secretion
Rabbits
Tosyl Compounds
Grant Support
ID/Acronym/Agency:
R01-DK-069929/DK/NIDDK NIH HHS; //Howard Hughes Medical Institute
Chemical
Reg. No./Substance:
0/Aminoquinolines; 0/Cations, Divalent; 0/Fluorescent Dyes; 0/Tosyl Compounds; 7SWW052N6R/N-(6-methoxy-8-quinolyl)-4-toluenesulfonamide; EC 3.6.1.10/H(+)-K(+)-Exchanging ATPase
Comments/Corrections

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