| Inhibition of cytochrome-c oxidase activity during prolonged hypoxia. | |
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MedLine Citation:
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PMID: 7611433 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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During acute (< 30 min) hypoxia, cellular respiration is independent of the O2 concentration as long as PO2 remains above a critical value (5-10 Torr). Similarly, state 3 respiration by isolated mitochondria is independent of PO2 above a critical tension of 2-4 Torr. However, rat hepatocytes demonstrate a reversible suppression of respiration and an increase in NAD(P)H concentration during prolonged (2-24 h), but not acute hypoxia [P. T. Schumacker, N. Chandel, and A. G. N. Augusti. Am. J. Physiol. 265 (Lung Cell. Mol. Physiol. 9): L395-L402, 1993]. This study tested whether respiration is similarly inhibited in isolated mitochondria exposed to low PO2 for prolonged periods and whether cytochrome-c oxidase participates in this response. Coupled rat liver mitochondria were incubated under low oxygen conditions (PO2 < 2 Torr) for 2 h. State 3 respiration after reoxygenation to PO2 = 20 Torr was then compared with the value obtained subsequently at 100 Torr. Using succinate and ADP as substrates, we determined that state 3 respiration at 20 Torr was 61.0 +/- 8.4% of the subsequent value at 100 Torr (P < 0.05). By contrast, control mitochondria reoxygenated to 100 Torr first and 20 Torr subsequently showed no significant difference at the two O2 tensions (P = NS).(ABSTRACT TRUNCATED AT 250 WORDS) |
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Authors:
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N Chandel; G R Budinger; R A Kemp; P T Schumacker |
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Publication Detail:
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Type: Journal Article; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
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Title: The American journal of physiology Volume: 268 ISSN: 0002-9513 ISO Abbreviation: Am. J. Physiol. Publication Date: 1995 Jun |
Date Detail:
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Created Date: 1995-08-15 Completed Date: 1995-08-15 Revised Date: 2007-11-14 |
Medline Journal Info:
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Nlm Unique ID: 0370511 Medline TA: Am J Physiol Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: L918-25 Citation Subset: IM |
Affiliation:
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Department of Medicine, University of Chicago, Illinois 60637, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Calcimycin / pharmacology Cell Hypoxia Electron Transport Complex IV / antagonists & inhibitors* Kinetics Male Mitochondria, Liver / enzymology*, metabolism Oxidative Phosphorylation Oxygen / pharmacology Oxygen Consumption / drug effects Partial Pressure Rats Rats, Sprague-Dawley |
| Grant Support | |
ID/Acronym/Agency:
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HL-07605/HL/NHLBI NIH HHS; HL-32646/HL/NHLBI NIH HHS; HL-35440/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
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52665-69-7/Calcimycin; 7782-44-7/Oxygen; EC 1.9.3.1/Electron Transport Complex IV |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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