| Muscle structure and performance capacity of Himalayan Sherpas. | |
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MedLine Citation:
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PMID: 1864773 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The ultrastructure of the vastus lateralis muscle of Sherpas from Nepal [5 males; age 28 +/- 2.8 (SD) yr, indirect maximal O2 consumption 48.5 +/- 5.4 ml.kg(-1).min(-1)] was assessed and compared with those of sedentary lowlanders and of Caucasian climbers before and after high-altitude exposure. The mean cross-sectional area of the fibers was 3,186 +/- 521 microns2, i.e., similar to those of Caucasian elite high-altitude climbers (3,108 +/- 303 microns2) and a group of climbers after a 6- to 8-wk sojourn at 5,000-8,600 m (3,360 +/- 580 microns2) but significantly (P less than 0.05) smaller than that of unacclimatized climbers (4,170 +/- 710 microns2) and slightly, although not significantly, lower than that of sedentary lowlanders (3,640 +/- 260 microns2). The number of capillaries per square millimeter of muscle cross section was 467 +/- 22, not significantly smaller than those of climbers on return from a Himalayan expedition (538 +/- 89) and elite high-altitude climbers (542 +/- 127) but significantly (P less than 0.05) greater than that of sedentary lowlanders (387 +/- 25). The volume density of mitochondria was 3.96 +/- 0.54%, significantly (P less than 0.05) less than the values found for any other investigated group, including sedentary subjects at sea level (4.74 +/- 0.30%). It is concluded that Sherpas, like acclimatized Caucasian climbers, are characterized by 1) facilitated convective and diffusive muscle O2 flow conditions and 2) a higher maximal O2 consumption-to-mitochondrial volume ratio than lowlanders despite a reduced mitochondrial volume density. |
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Authors:
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B Kayser; H Hoppeler; H Claassen; P Cerretelli |
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Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: Journal of applied physiology (Bethesda, Md. : 1985) Volume: 70 ISSN: 8750-7587 ISO Abbreviation: J. Appl. Physiol. Publication Date: 1991 May |
Date Detail:
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Created Date: 1991-09-09 Completed Date: 1991-09-09 Revised Date: 2004-11-17 |
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: 1938-42 Citation Subset: IM; S |
Affiliation:
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Department of Physiology, Centre Médical Universitaire, Geneva, Switzerland. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Acclimatization
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physiology* Adult Altitude* Anoxia / pathology, physiopathology Capillaries / ultrastructure Humans Male Mitochondria, Muscle / ultrastructure Mountaineering Muscle Contraction Muscles / blood supply, physiology, ultrastructure* Nepal Physical Endurance |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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