| Very high pressures are required to cause stress failure of pulmonary capillaries in thoroughbred racehorses. | |
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MedLine Citation:
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PMID: 9134908 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Thoroughbred horses develop extremely high pulmonary vascular pressures during galloping, all horses in training develop exercise-induced pulmonary hemorrhage, and we have shown that this is caused by stress failure of pulmonary capillaries. It is known that the capillary transmural pressure (Ptm) necessary for stress failure is higher in dogs than in rabbits. The present study was designed to determine this value in horses. The lungs from 15 Thoroughbred horses were perfused with autologous blood at Ptm values (midlung) of 25, 50, 75, 100 and 150 mmHg, and then perfusion fixed, and samples (dorsal and ventral, from caudal region) were examined by electron microscopy. Few disruptions of capillary endothelium were observed at Ptm < or = 75 mmHg, and 5.3 +/- 2.2 and 4.3 +/- 0.7 breaks/mm endothelium were found at 100 and 150 mmHg Ptm, respectively. Blood-gas barrier thickness did not change with Ptm. At low Ptm, interstitial thickness was greater than previously found in rabbits but not in dogs. We conclude that the Ptm required to cause stress failure of pulmonary capillaries is between 75 and 100 mmHg and is greater in Thoroughbred horses than in both rabbits and dogs. |
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Authors:
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E K Birks; O Mathieu-Costello; Z Fu; W S Tyler; J B West |
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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: Journal of applied physiology (Bethesda, Md. : 1985) Volume: 82 ISSN: 8750-7587 ISO Abbreviation: J. Appl. Physiol. Publication Date: 1997 May |
Date Detail:
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Created Date: 1997-07-21 Completed Date: 1997-07-21 Revised Date: 2008-11-21 |
Medline Journal Info:
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Nlm Unique ID: 8502536 Medline TA: J Appl Physiol Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 1584-92 Citation Subset: IM |
Affiliation:
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Department of Medicine, School of Medicine, University of California, San Diego, La Jolla 92093-0623, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Capillaries / pathology, physiology, ultrastructure Endothelium, Vascular / pathology, ultrastructure Epithelium / pathology, ultrastructure Female Horses / physiology* Male Microscopy, Electron Physical Exertion / physiology Pressure Pulmonary Alveoli / blood supply*, physiology, ultrastructure Species Specificity Stress, Physiological / physiopathology* |
| Grant Support | |
ID/Acronym/Agency:
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HL-17731/HL/NHLBI NIH HHS; R01 HL-46910/HL/NHLBI NIH HHS |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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