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dc.contributor.authorAguilar, Miguel
dc.contributor.authorGonzalez-Candia, Alejandro
dc.contributor.authorRodriguez, Jorge
dc.contributor.authorCarrasco-Pozo, Catalina
dc.contributor.authorCanas, Daniel
dc.contributor.authorGarcia-Herrera, Claudio
dc.contributor.authorHerrera, Emilio A
dc.contributor.authorCastillo, Rodrigo L
dc.date.accessioned2019-05-29T12:35:22Z
dc.date.available2019-05-29T12:35:22Z
dc.date.issued2018
dc.identifier.issn1422-0067
dc.identifier.doi10.3390/ijms19020366
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.
dc.description.peerreviewedYes
dc.languageEnglish
dc.language.isoeng
dc.publisherMDPI
dc.publisher.placeSwitzerland
dc.relation.ispartofchapter366
dc.relation.ispartofpagefrom1
dc.relation.ispartofpageto15
dc.relation.ispartofissue2
dc.relation.ispartofjournalInternational Journal of Molecular Sciences
dc.relation.ispartofvolume19
dc.subject.fieldofresearchOther chemical sciences
dc.subject.fieldofresearchGenetics
dc.subject.fieldofresearchOther biological sciences
dc.subject.fieldofresearchCardiovascular medicine and haematology not elsewhere classified
dc.subject.fieldofresearchcode3499
dc.subject.fieldofresearchcode3105
dc.subject.fieldofresearchcode3199
dc.subject.fieldofresearchcode320199
dc.titleMechanisms of cardiovascular protection associated with intermittent hypobaric hypoxia exposure in a rat model: Role of oxidative stress
dc.typeJournal article
dc.type.descriptionC1 - Articles
dc.type.codeC - Journal Articles
dcterms.licensehttp://creativecommons.org/licenses/by/4.0/
dc.description.versionVersion of Record (VoR)
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.
gro.hasfulltextFull Text
gro.griffith.authorCarrasco Pozo, Catalina A.


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