| Maintenance of cellular acidification in cyanide-treated hepatocytes results from inhibition of Na+/H+ exchange. | |
| | |
MedLine Citation:
|
PMID: 8203534 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Inhibition of respiration by metabolic inhibitors or hypoxia is accompanied by intracellular acidification. Although this acidification is known to promote cell survival during hypoxia, little is known about its mechanism. Given that the Na+/H+ exchanger is known to be a major component of pH regulation in normal hepatocytes, the aim of this study was to determine the effects of inhibition of mitochondrial respiration on intracellular pH (pHi) regulation and Na+/H+ exchange. Cyanide (CN-; 5 mM) plus fructose (20 mM) were used as a model of hypoxic acidosis. pHi was measured with quantitative fluorescence microscopy of cells loaded with the pH indicator, 2',7'-bis-(2-carboxyethyl)-5,6-carboxyfluorescein. In control cells, pHi was 7.09 +/- 0.01 SE (n = 106). After 60 min in CN(-)-fructose, pHi fell to 6.74 +/- 0.01 (n = 129, P < 0.001). The pHi recovery rate (expressed as mmol H+.l-1.min-1) was determined under both conditions after acid loading by transient exposure and removal of 20 mM NH4Cl. Control and CN(-)-treated cells recovered at 3.59 +/- 0.25 (n = 42) and 0.69 +/- 0.09 (n = 38, P < 0.001), respectively. Amiloride treatment (1 mM) in the absence of CN- reduced pHi recovery similarly to that caused by CN- (0.34 +/- 0.07, n = 14). CN(-)-treated cells exposed to amiloride demonstrated no additional inhibition (efflux rate 0.65 +/- 0.11, n = 27), suggesting that the inhibition is directed at Na+/H+ exchange. Twenty minutes after CN- removal, CN(-)-treated cells regained their ability to recover from an acid load, thus demonstrating the reversibility of this effect.(ABSTRACT TRUNCATED AT 250 WORDS) |
| | |
Authors:
|
J A Schoenecker; S A Weinman |
Related Documents
:
|
18322734 - Trehalose-producing enzymes mtsase and mthase in anabaena 7120 under nacl stress. 16190474 - Segmenting and tracking fluorescent cells in dynamic 3-d microscopy with coupled active... 1591834 - Quantitative histological analysis of the human sinoatrial node during growth and aging. 1415564 - Cell volume regulation in rat thin ascending limb of henle's loop. 151224 - Thymus quantitative morphological changes during ccl4-induced liver cirrhosis. 16714094 - Chickgce: a novel germ cell est database for studying the early developmental stage in ... |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
|
Title: The American journal of physiology Volume: 266 ISSN: 0002-9513 ISO Abbreviation: Am. J. Physiol. Publication Date: 1994 May |
Date Detail:
|
Created Date: 1994-07-07 Completed Date: 1994-07-07 Revised Date: 2007-11-14 |
Medline Journal Info:
|
Nlm Unique ID: 0370511 Medline TA: Am J Physiol Country: UNITED STATES |
Other Details:
|
Languages: eng Pagination: G892-8 Citation Subset: IM |
Affiliation:
|
Department of Internal Medicine, University of Texas Medical Branch, Galveston 77555. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Ammonium Chloride
/
pharmacology Animals Cells, Cultured Cyanides / pharmacology* Hydrogen-Ion Concentration Kinetics Lactates / analysis Liver / drug effects, metabolism* Male Microscopy, Fluorescence Rats Rats, Sprague-Dawley Regression Analysis Sodium-Hydrogen Antiporter / antagonists & inhibitors* Time Factors |
| Grant Support | |
ID/Acronym/Agency:
|
DK-42917/DK/NIDDK NIH HHS |
| Chemical | |
Reg. No./Substance:
|
0/Cyanides; 0/Lactates; 0/Sodium-Hydrogen Antiporter; 12125-02-9/Ammonium Chloride |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Regulation of glucose-dependent insulinotropic peptide gene expression by a glucose meal.
Next Document: Pleiotropic effect of LEC mutation: a rodent model of Wilson's disease.