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dc.contributor.authorSkovgaard, N.
dc.contributor.authorAbe, Augusto Shinya [UNESP]
dc.contributor.authorAndrade, Denis V. [UNESP]
dc.contributor.authorWang, T.
dc.identifier.citationAmerican Journal of Physiology-regulatory Integrative and Comparative Physiology. Bethesda: Amer Physiological Soc, v. 289, n. 5, p. R1280-R1288, 2005.
dc.description.abstractLow O-2 levels in the lungs of birds and mammals cause constriction of the pulmonary vasculature that elevates resistance to pulmonary blood flow and increases pulmonary blood pressure. This hypoxic pulmonary vasoconstriction (HPV) diverts pulmonary blood flow from poorly ventilated and hypoxic areas of the lung to more well-ventilated parts and is considered important for the local matching of ventilation to blood perfusion. In the present study, the effects of acute hypoxia on pulmonary and systemic blood flows and pressures were measured in four species of anesthetized reptiles with diverse lung structures and heart morphologies: varanid lizards (Varanus exanthematicus), caimans (Caiman latirostris), rattlesnakes (Crotalus durissus), and tegu lizards (Tupinambis merianae). As previously shown in turtles, hypoxia causes a reversible constriction of the pulmonary vasculature in varanids and caimans, decreasing pulmonary vascular conductance by 37 and 31%, respectively. These three species possess complex multicameral lungs, and it is likely that HPV would aid to secure ventilation-perfusion homogeneity. There was no HPV in rattlesnakes, which have structurally simple lungs where local ventilation-perfusion inhomogeneities are less likely to occur. However, tegu lizards, which also have simple unicameral lungs, did exhibit HPV, decreasing pulmonary vascular conductance by 32%, albeit at a lower threshold than varanids and caimans (6.2 kPa oxygen in inspired air vs. 8.2 and 13.9 kPa, respectively). Although these observations suggest that HPV is more pronounced in species with complex lungs and functionally divided hearts, it is also clear that other components are involved.en
dc.publisherAmer Physiological Soc
dc.relation.ispartofAmerican Journal of Physiology: Regulatory Integrative and Comparative Physiology
dc.sourceWeb of Science
dc.subjectpulmonary circulationpt
dc.subjectsystemic circulationpt
dc.titleHypoxic pulmonary vasoconstriction in reptiles: a comparative study of four species with different lung structures and pulmonary blood pressuresen
dcterms.rightsHolderAmer Physiological Soc
dc.contributor.institutionAarhus University (AU)
dc.contributor.institutionUniversidade Estadual Paulista (Unesp)
dc.description.affiliationAarhus Univ, Dept Zoophysiol, DK-8000 Aarhus, Denmark
dc.description.affiliationUniv Estadual Paulista, Dept Zool, São Paulo, Brazil
dc.description.affiliationUnespUniv Estadual Paulista, Dept Zool, São Paulo, Brazil
dc.rights.accessRightsAcesso restrito
unesp.campusUniversidade Estadual Paulista (Unesp), Instituto de Biociências, Rio Claropt
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