Journal article
Hypoxia and exercise increase the transpulmonary passage of 99mTc-labeled albumin particles in humans
PloS one, Vol.9(7), pp.e101146-e101146
2014
DOI: 10.1371/journal.pone.0101146
PMCID: PMC4094383
PMID: 25013985
Abstract
Intrapulmonary arteriovenous anastomoses (IPAVs) are large diameter connections that allow blood to bypass the lung capillaries and may provide a route for right-to-left embolus transmission. These anastomoses are recruited by exercise and catecholamines and hypoxia. Yet, whether IPAVs are recruited via direct, oxygen sensitive regulatory mechanisms or indirect effects secondary to redistribution pulmonary blood flow is unknown. Here, we hypothesized that the addition of exercise to hypoxic gas breathing, which increases cardiac output, would augment IPAVs recruitment in healthy humans. To test this hypothesis, we measured the transpulmonary passage of 99mTc-macroaggregated albumin particles (99mTc-MAA) in seven healthy volunteers, at rest and with exercise at 85% of volitional max, with normoxic (FIO2 = 0.21) and hypoxic (FIO2 = 0.10) gas breathing. We found increased 99mTc-MAA passage in both exercise conditions and resting hypoxia. However, contrary to our hypothesis, we found the greatest 99mTc-MAA passage with resting hypoxia. As an additional, secondary endpoint, we also noted that the transpulmonary passage of 99mTc-MAA was well-correlated with the alveolar-arterial oxygen difference (A-aDO2) during exercise. While increased cardiac output has been proposed as an important modulator of IPAVs recruitment, we provide evidence that the modulation of blood flow through these pathways is more complex and that increasing cardiac output does not necessarily increase IPAVs recruitment. As we discuss, our data suggest that the resistance downstream of IPAVs is an important determinant of their perfusion.
Details
- Title: Subtitle
- Hypoxia and exercise increase the transpulmonary passage of 99mTc-labeled albumin particles in humans
- Creators
- Melissa L Bates - Department of Pediatrics, Critical Care Division and the John Rankin Laboratory of Pulmonary Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of AmericaEmily T Farrell - Department of Pediatrics, Critical Care Division and the John Rankin Laboratory of Pulmonary Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of AmericaAlyssa Drezdon - Department of Pediatrics, Critical Care Division and the John Rankin Laboratory of Pulmonary Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of AmericaJoseph E Jacobson - Department of Pediatrics, Critical Care Division and the John Rankin Laboratory of Pulmonary Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of America; Michigan State University College of Human Medicine, East Lansing, Michigan, United States of AmericaScott B Perlman - Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of AmericaMarlowe W Eldridge - Department of Pediatrics, Critical Care Division and the John Rankin Laboratory of Pulmonary Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of America; Departments of Biomedical Engineering and Kinesiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of America
- Resource Type
- Journal article
- Publication Details
- PloS one, Vol.9(7), pp.e101146-e101146
- DOI
- 10.1371/journal.pone.0101146
- PMID
- 25013985
- PMCID
- PMC4094383
- NLM abbreviation
- PLoS One
- ISSN
- 1932-6203
- eISSN
- 1932-6203
- Publisher
- Public Library of Science; United States
- Grant note
- 5R01HL086897 / NHLBI NIH HHS 5T32HL007654 / NHLBI NIH HHS R01 HL086897 / NHLBI NIH HHS
- Language
- English
- Date published
- 2014
- Academic Unit
- Stead Family Department of Pediatrics; Health, Sport, and Human Physiology ; Internal Medicine
- Record Identifier
- 9984002464302771
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