| Developmental changes in cardiac recovery from anoxia-reoxygenation. | |
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MedLine Citation:
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PMID: 12121851 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The developing cardiovascular system is known to operate normally in a hypoxic environment. However, the functional and ultrastructural recovery of embryonic/fetal hearts subjected to anoxia lasting as long as hypoxia/ischemia performed in adult animal models remains to be investigated. Isolated spontaneously beating hearts from Hamburger-Hamilton developmental stages 14 (14HH), 20HH, 24HH, and 27HH chick embryos were subjected in vitro to 30 or 60 min of anoxia followed by 60 min of reoxygenation. Morphological alterations and apoptosis were assessed histologically and by transmission electron microscopy. Anoxia provoked an initial tachycardia followed by bradycardia leading to complete cardiac arrest, except for in the youngest heart, which kept beating. Complete atrioventricular block appeared after 9.4 +/- 1.1, 1.7 +/- 0.2, and 1.6 +/- 0.3 min at stages 20HH, 24HH, and 27HH, respectively. At reoxygenation, sinoatrial activity resumed first in the form of irregular bursts, and one-to-one atrioventricular conduction resumed after 8, 17, and 35 min at stages 20HH, 24HH, and 27HH, respectively. Ventricular shortening recovered within 30 min except at stage 27HH. After 60 min of anoxia, stage 27HH hearts did not retrieve their baseline activity. Whatever the stage and anoxia duration, nuclear and mitochondrial swelling observed at the end of anoxia were reversible with no apoptosis. Thus the embryonic heart is able to fully recover from anoxia/reoxygenation although its anoxic tolerance declines with age. Changes in cellular homeostatic mechanisms rather than in energy metabolism may account for these developmental variations. |
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Authors:
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David Sedmera; Pavel Kucera; Eric Raddatz |
Publication Detail:
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Type: In Vitro; Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: American journal of physiology. Regulatory, integrative and comparative physiology Volume: 283 ISSN: 0363-6119 ISO Abbreviation: Am. J. Physiol. Regul. Integr. Comp. Physiol. Publication Date: 2002 Aug |
Date Detail:
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Created Date: 2002-07-17 Completed Date: 2002-08-15 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 100901230 Medline TA: Am J Physiol Regul Integr Comp Physiol Country: United States |
Other Details:
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Languages: eng Pagination: R379-88 Citation Subset: IM |
Affiliation:
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Institute of Physiology, Faculty of Medicine, University of Lausanne, CH-1005 Lausanne, Switzerland. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Animals Anoxia / physiopathology* Bradycardia / physiopathology Chick Embryo Extracellular Space / chemistry, metabolism Heart / drug effects, embryology*, physiopathology* Heart Block / physiopathology Heart Rate / drug effects Hydrogen-Ion Concentration Lactic Acid / biosynthesis Oxygen / pharmacology* Recovery of Function* Tachycardia / physiopathology Time Factors |
| Chemical | |
Reg. No./Substance:
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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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