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dc.contributor.authorAguilar, Miguelen_US
dc.contributor.authorGonzalez-Candia, Alejandroen_US
dc.contributor.authorRodriguez, Jorgeen_US
dc.contributor.authorCarrasco Pozo, Catalinaen_US
dc.contributor.authorCanas, Danielen_US
dc.contributor.authorGarcia-Herrera, Claudioen_US
dc.contributor.authorHerrera, Emilioen_US
dc.contributor.authorCastillo, Rodrigoen_US
dc.date.accessioned2019-05-29T12:35:22Z
dc.date.available2019-05-29T12:35:22Z
dc.date.issued2018en_US
dc.identifier.issn1422-0067en_US
dc.identifier.doi10.3390/ijms19020366en_US
dc.identifier.urihttp://hdl.handle.net/10072/380319
dc.description.abstractMore than 140 million people live and works (in a chronic or intermittent form) above 2500 m worldwide and 35 million live in the Andean Mountains. Furthermore, in Chile, it is estimated that 55,000 persons work in high altitude shifts, where stays at lowlands and interspersed with working stays at highlands. Acute exposure to high altitude has been shown to induce oxidative stress in healthy human lowlanders, due to an increase in free radical formation and a decrease in antioxidant capacity. However, in animal models, intermittent hypoxia (IH) induce preconditioning, like responses and cardioprotection. Here, we aimed to describe in a rat model the responses on cardiac and vascular function to 4 cycles of intermittent hypobaric hypoxia (IHH). Twelve adult Wistar rats were randomly divided into two equal groups, a four-cycle of IHH, and a normobaric hypoxic control. Intermittent hypoxia was induced in a hypobaric chamber in four continuous cycles (1 cycle = 4 days hypoxia + 4 days normoxia), reaching a barometric pressure equivalent to 4600 m of altitude (428 Torr). At the end of the first and fourth cycle, cardiac structural, and functional variables were determined by echocardiography. Thereafter, ex vivo vascular function and biomechanical properties were determined in femoral arteries by wire myography. We further measured cardiac oxidative stress biomarkers (4-Hydroxy-nonenal, HNE; nytrotirosine, NT), reactive oxygen species (ROS) sources (NADPH and mitochondrial), and antioxidant enzymes activity (catalase, CAT; glutathione peroxidase, GPx, and superoxide dismutase, SOD). Our results show a higher ejection and shortening fraction of the left ventricle function by the end of the 4th cycle. Further, femoral vessels showed an improvement of vasodilator capacity and diminished stiffening. Cardiac tissue presented a higher expression of antioxidant enzymes and mitochondrial ROS formation in IHH, as compared with normobaric hypoxic controls. IHH exposure determines a preconditioning effect on the heart and femoral artery, both at structural and functional levels, associated with the induction of antioxidant defence mechanisms. However, mitochondrial ROS generation was increased in cardiac tissue. These findings suggest that initial states of IHH are beneficial for cardiovascular function and protection.en_US
dc.description.peerreviewedYesen_US
dc.languageEnglishen_US
dc.publisherMDPIen_US
dc.publisher.placeSwitzerlanden_US
dc.relation.ispartofchapter366en_US
dc.relation.ispartofpagefrom1en_US
dc.relation.ispartofpageto15en_US
dc.relation.ispartofissue2en_US
dc.relation.ispartofjournalInternational Journal of Molecular Sciencesen_US
dc.relation.ispartofvolume19en_US
dc.subject.fieldofresearchCardiorespiratory Medicine and Haematology not elsewhere classifieden_US
dc.subject.fieldofresearchOther Chemical Sciencesen_US
dc.subject.fieldofresearchGeneticsen_US
dc.subject.fieldofresearchcode110299en_US
dc.subject.fieldofresearchcode0399en_US
dc.subject.fieldofresearchcode0604en_US
dc.titleMechanisms of cardiovascular protection associated with intermittent hypobaric hypoxia exposure in a rat model: Role of oxidative stressen_US
dc.typeJournal articleen_US
dc.type.descriptionC1 - Articlesen_US
dc.type.codeC - Journal Articlesen_US
dcterms.licensehttp://creativecommons.org/licenses/by/4.0/en_US
dc.description.versionPublisheden_US
gro.rights.copyright© 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, providing that the work is properly cited.en_US
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