Document Detail


Hypoxia-inducible carbonic anhydrase IX expression is insufficient to alleviate intracellular metabolic acidosis in the muscle of zebrafish, Danio rerio.
MedLine Citation:
PMID:  18945954     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Recent evidence suggests that carbonic anhydrase (CA) IX in humans is under the regulatory control of hypoxia-inducible factor and is overexpressed in certain cancers. However, little is known of its presence in nonmammalian vertebrates or its physiological function in any vertebrate. The objective of this study was to examine and characterize the presence, distribution, induction by hypoxia, and physiological function of CA IX in the zebrafish. Zebrafish CA IX was highly expressed in the eye, brain, and gastrointestinal tract and showed increased expression in the eye, brain, and muscle in response to hypoxia (water Po(2) = 24 mmHg). The hypothesis that increased CA IX expression during hypoxia would act to attenuate intracellular acidosis was then examined. Muscle intracellular pH (pH(i)) decreased after 4 h of hypoxic exposure (from 7.15 +/- 0.02 to 7.06 +/- 0.01 pH units) and did not recover by 24 h. Manipulation of extracellular CA activity via intraperitoneal injection of either bovine CA or the selective extracellular CA inhibitor F3500 revealed that although increased CA activity could fully restore pH(i), removal of extracellular activity did not result in further acidosis. An exercise-induced acidosis was also attenuated in fish treated with bovine CA; however, the increased extracellular CA expression resulting from hypoxia had no affect. These data suggest that although extracellular CA can potentially minimize the impact of hypoxia on muscle pH(i), the actual level of extracellular CA activity is likely insufficient to achieve this goal, even when enhanced by hypoxia-induced increases in CA IX expression.
Authors:
Andrew J Esbaugh; S F Perry; K M Gilmour
Related Documents :
3017274 - Calcium carbonate precipitation in bicarbonate hemodialysis.
8094454 - Intraduodenal delivery of intrinsically and extrinsically labelled caco3 in the rat: ef...
21067924 - 7,8-disubstituted- but not 6,7-disubstituted coumarins selectively inhibit the transmem...
21358644 - Presynaptic hcn1 channels regulate cav3.2 activity and neurotransmission at select cort...
8867124 - Whole cell calcium currents in acutely isolated olfactory bulb output neurons of the rat.
16037094 - Electrophysiological characterization of native na+-hco3- cotransporter current in bovi...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2008-10-22
Journal Detail:
Title:  American journal of physiology. Regulatory, integrative and comparative physiology     Volume:  296     ISSN:  0363-6119     ISO Abbreviation:  Am. J. Physiol. Regul. Integr. Comp. Physiol.     Publication Date:  2009 Jan 
Date Detail:
Created Date:  2008-12-30     Completed Date:  2009-02-06     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100901230     Medline TA:  Am J Physiol Regul Integr Comp Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  R150-60     Citation Subset:  IM    
Affiliation:
Dept. of Biology and Centre for Advanced Research in Environmental Genomics, Univ. of Ottawa, Ottawa, Ontario, Canada K1N 6N5. aesbaugh@uottawa.ca
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Acid-Base Equilibrium* / drug effects
Acidosis / enzymology*
Animals
Anoxia / enzymology*
Brain / enzymology
Carbonic Anhydrase Inhibitors / administration & dosage
Carbonic Anhydrases / administration & dosage,  biosynthesis*,  chemistry,  genetics
Cattle
Enzyme Induction
Eye / enzymology
Fish Proteins / biosynthesis*,  chemistry,  genetics
Gastrointestinal Tract / enzymology
Hydrogen-Ion Concentration
Injections, Intraperitoneal
Muscle, Skeletal / drug effects,  enzymology*
Phylogeny
Polyethylene Glycols / administration & dosage
RNA, Messenger / biosynthesis
Response Elements
Thiadiazoles / administration & dosage
Time Factors
Zebrafish / metabolism*
Chemical
Reg. No./Substance:
0/Carbonic Anhydrase Inhibitors; 0/F 3500; 0/Fish Proteins; 0/Polyethylene Glycols; 0/RNA, Messenger; 0/Thiadiazoles; EC 4.2.1.1/Carbonic Anhydrases

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Increased renal adrenomedullin expression in rats with ureteral obstruction.
Next Document:  Inhibitory effects and mechanisms of intestinal electrical stimulation on gastric tone, antral contr...