| The canine spleen in oxygen transport: gas exchange and hemodynamic responses to splenectomy. | |
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MedLine Citation:
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PMID: 17673565 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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In athletic animals the spleen induces acute polycythemia by dynamic contraction that releases red blood cells into the circulation in response to increased O(2) demand and metabolic stress; when energy demand is relieved, the polycythemia is rapidly reversed by splenic relaxation. We have shown in adult foxhounds that splenectomy eliminates exercise-induced polycythemia, thereby reducing peak O(2) uptake and lung diffusing capacity for carbon monoxide (DL(CO)) as well as exaggerating preexisting DL(CO) impairment imposed by pneumonectomy (Dane DM, Hsia CC, Wu EY, Hogg RT, Hogg DC, Estrera AS, Johnson RL Jr. J Appl Physiol 101: 289-297, 2006). To examine whether the postsplenectomy reduction in DL(CO) leads to abnormalities in O(2) diffusion, ventilation-perfusion inequality, or hemodynamic function, we studied these animals via the multiple inert gas elimination technique at rest and during exercise at a constant workload equivalent to 50% or 80% of peak O(2) uptake while breathing 21% and 14% O(2) in balanced order. From rest to exercise after splenectomy, minute ventilation was significantly elevated with respect to O(2) uptake compared with exercise before splenectomy; cardiac output, O(2) delivery, and mean pulmonary and systemic arterial blood pressures were 10-20% lower, while O(2) extraction was elevated with respect to O(2) uptake. Ventilation-perfusion inequality was unchanged, but O(2) diffusing capacities of lung (DL(O2)) and peripheral tissue during exercise were lower with respect to cardiac output postsplenectomy by 32% and 25%, respectively. The relationship between DL(O2) and DL(CO) was unchanged by splenectomy. We conclude that the canine spleen regulates both convective and diffusive O(2) transport during exercise to increase maximal O(2) uptake. |
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Authors:
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Connie C W Hsia; Robert L Johnson; D Merrill Dane; Eugene Y Wu; Aaron S Estrera; Harrieth E Wagner; Peter D Wagner |
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Publication Detail:
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Type: Journal Article; Research Support, N.I.H., Extramural Date: 2007-08-02 |
Journal Detail:
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Title: Journal of applied physiology (Bethesda, Md. : 1985) Volume: 103 ISSN: 8750-7587 ISO Abbreviation: J. Appl. Physiol. Publication Date: 2007 Nov |
Date Detail:
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Created Date: 2007-10-29 Completed Date: 2008-01-08 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: 1496-505 Citation Subset: IM |
Affiliation:
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Dept. of Internal Medicine, Univ. of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9034, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Blood Pressure Blood Volume Carbon Dioxide / metabolism Carbon Monoxide / metabolism Cardiac Output Diffusion Dogs Erythrocyte Volume Hematocrit Hemodynamics* Hemoglobins / metabolism Hydrogen-Ion Concentration Lung / metabolism* Male Oxygen / blood, metabolism* Oxygen Consumption Physical Exertion / physiology* Pulmonary Diffusing Capacity Pulmonary Gas Exchange* Spleen / physiology*, surgery Splenectomy* Vascular Resistance |
| Grant Support | |
ID/Acronym/Agency:
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HL040070/HL/NHLBI NIH HHS; HL054060/HL/NHLBI NIH HHS; HL062873/HL/NHLBI NIH HHS; R01 HL045716/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
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0/Hemoglobins; 124-38-9/Carbon Dioxide; 630-08-0/Carbon Monoxide; 7782-44-7/Oxygen |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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