| Prolonged stable hypothermia: effect on blood gases and pH in rats and ground squirrels. | |
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MedLine Citation:
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PMID: 1539726 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Richardson's ground squirrels [body temperature (Tb) 7 degrees C] survive prolonged stable hypothermia for three times as long as do rats (Tb 19 degrees C) (72 vs. 24 h). We have examined the changes in blood gases and acid-base state to assess whether these contribute to this difference in survival time. None of the variables (measured at ambient temperature of 25 degrees C) differed significantly between rats and ground squirrels before hypothermic induction. During cooling, neither hematocrit nor plasma lactate changed significantly, but arterial and venous PO2 and PCO2 increased and arterial and venous pH decreased in both groups. During prolonged hypothermia, hematocrit increased significantly in rats (58.8 +/- 1.7% at 24 h) but not in ground squirrels (39.1 +/- 1.0% at 72 h). Both species maintained stable arterial blood gases but showed decreased venous PO2; arterial and venous pH decreased significantly with time in both species in conjunction with increased plasma lactate. These patterns of decreased venous PO2 and increased plasma lactate suggest that reduced tissue oxygenation occurs during hypothermia. This happens earlier in rats at a Tb of 19 degrees C than in ground squirrels at a Tb of 7 degrees C, possibly as a result of increased hematocrit in hypothermic rats. Remedial measures directed at improving tissue O2 delivery may therefore prolong the hypothermic survival of rats. |
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Authors:
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M D McArthur; M L Jourdan; L C Wang |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: The American journal of physiology Volume: 262 ISSN: 0002-9513 ISO Abbreviation: Am. J. Physiol. Publication Date: 1992 Feb |
Date Detail:
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Created Date: 1992-04-01 Completed Date: 1992-04-01 Revised Date: 2006-11-15 |
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: R190-7 Citation Subset: IM |
Affiliation:
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Department of Zoology, University of Alberta, Edmonton, Canada. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Carbon Dioxide / blood* Hematocrit Hydrogen-Ion Concentration Hypothermia / blood*, metabolism Lactates / blood Lactic Acid Male Osmolar Concentration Oxygen / blood* Rats Rats, Inbred Strains Sciuridae |
| Chemical | |
Reg. No./Substance:
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0/Lactates; 124-38-9/Carbon Dioxide; 50-21-5/Lactic Acid; 7782-44-7/Oxygen |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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