Perinatal cardiopulmonary adaptation to the thin air of the Alto Andino by a native Altiplano dweller, the llama
Author
dc.contributor.author
Reyes Catalán, Víctor
Author
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Herrera Videla, Emilio
Author
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Ebensperger Darrouy, Germán
Author
dc.contributor.author
Sanhueza Reinoso, Emilia
Author
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Giussani, D. A.
Author
dc.contributor.author
Llanos Mansilla, Jorge
Admission date
dc.date.accessioned
2020-10-28T22:50:41Z
Available date
dc.date.available
2020-10-28T22:50:41Z
Publication date
dc.date.issued
2020
Cita de ítem
dc.identifier.citation
J Appl Physiol 129: 152–161, 2020
es_ES
Identifier
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10.1152/japplphysiol.00800.2019
Identifier
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https://repositorio.uchile.cl/handle/2250/177445
Abstract
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Most mammals have a poor tolerance to hypoxia, and prolonged O-2 restriction can lead to organ injury, particularly during fetal and early postnatal life. Nevertheless, the llama (Lama Glama) has evolved efficient mechanisms to adapt to acute and chronic perinatal hypoxia. One striking adaptation is the marked peripheral vasoconstriction measured in the llama fetus in response to acute hypoxia. which allows efficient redistribution of cardiac output toward the fetal heart and adrenal glands. This strong peripheral vasoconstrictor tone is triggered by a carotid body reflex and critically depends on alpha-adrenergic signaling. A second adaptation is the ability of the llama fetus to protect its brain against hypoxic damage. During hypoxia, in the llama fetus there is no significant increase in brain blood flow. Instead, there is a fall in brain O-2 consumption and temperature. together with a decrease of Na+-K+-ATPase activity and Na+ channels expression, protecting against seizures and neuronal death. Finally, the newborn llama does not develop pulmonary hypertension in response to chronic hypoxia. In addition to maintaining basal pulmonary arterial pressure at normal levels the pulmonary arterial pressor response to acute hypoxia is lower in highland than in lowland llamas. The protection against hypoxic pulmonary arterial hypertension and pulmonary contractile hyperreactivity is partly due to increased hemoxygenase-carbon monoxide signaling and decreased Ca2+ sensitization in the newborn llama pulmonary vasculature. These three striking physiological adaptations of the llama allow this species to live and thrive under the chronic influence of the hypobaric hypoxia of life at high altitude.
es_ES
Patrocinador
dc.description.sponsorship
Comisión Nacional de Investigación Científica y Tecnológica (CONICYT)
CONICYT FONDECYT
1120605
1130424
1140647
1151119
Instituto de Ciencias Biomédicas, Universidad de Chile (Proyecto Puente - ICBM)
Vicerrectoría de Investigación y Desarrollo, Universidad de Chile (VID-Enlace)
ENL023f16