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Cardiac adaptation to high altitude in the plateau pika (Ochotona curzoniae)

The aim of this study was to assess maximal heart rate (HR) and heart morphological changes in high altitude living “plateau pikas” and rats bred at 2260 m. Rats and pikas were catheterized to measure HR (2260 m). After baseline measurements, 1 mg/kg of atropine (AT) and increasing doses of isoprote...

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Autores principales: Pichon, Aurélien, Zhenzhong, Bai, Marchant, Dominique, Jin, Guoen, Voituron, Nicolas, Haixia, Yun, Favret, Fabrice, Richalet, Jean-Paul, Ge, Ri-Li
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Blackwell Publishing Ltd 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3831927/
https://www.ncbi.nlm.nih.gov/pubmed/24303117
http://dx.doi.org/10.1002/phy2.32
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author Pichon, Aurélien
Zhenzhong, Bai
Marchant, Dominique
Jin, Guoen
Voituron, Nicolas
Haixia, Yun
Favret, Fabrice
Richalet, Jean-Paul
Ge, Ri-Li
author_facet Pichon, Aurélien
Zhenzhong, Bai
Marchant, Dominique
Jin, Guoen
Voituron, Nicolas
Haixia, Yun
Favret, Fabrice
Richalet, Jean-Paul
Ge, Ri-Li
author_sort Pichon, Aurélien
collection PubMed
description The aim of this study was to assess maximal heart rate (HR) and heart morphological changes in high altitude living “plateau pikas” and rats bred at 2260 m. Rats and pikas were catheterized to measure HR (2260 m). After baseline measurements, 1 mg/kg of atropine (AT) and increasing doses of isoproterenol (IsoP) (0.1, 1, 10, and 100 μg kg) were injected into animals. Right (RV) and left ventricles (LV) were removed to calculate Fulton's ratio (LV + septum (S) to RV weights) and to assess mRNA expression level of β1- and β2-adrenoceptors, muscarinic m1 and m2 receptors, and vascular endothelial growth factor (VEGF). Resting HR was significantly lower in rats than in pikas and increased after AT injection only in rats. IsoP injection induced a significant increase in HR in rat for all doses, which was systematically greater than in pikas. In pikas HR was slightly increased only after the two highest concentrations of IsoP. Fulton's ratio was greater in rats compared with pikas but the LV + S adjusted for body weight was greater in pikas. Pikas showed lower β1-adrenoceptors and muscarinic m2 receptors mRNA expression but larger VEGF mRNA expression than rats both in RV and LV. These results suggest that pikas have a lower maximal HR compared with rats certainly due to a decrease in β-adrenergic and muscarinic receptors mRNA expression. However, the LV hypertrophy probably led to an increase in stroke volume to maintain cardiac output in response to the cold and hypoxic environment.
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spelling pubmed-38319272013-12-03 Cardiac adaptation to high altitude in the plateau pika (Ochotona curzoniae) Pichon, Aurélien Zhenzhong, Bai Marchant, Dominique Jin, Guoen Voituron, Nicolas Haixia, Yun Favret, Fabrice Richalet, Jean-Paul Ge, Ri-Li Physiol Rep Original Research The aim of this study was to assess maximal heart rate (HR) and heart morphological changes in high altitude living “plateau pikas” and rats bred at 2260 m. Rats and pikas were catheterized to measure HR (2260 m). After baseline measurements, 1 mg/kg of atropine (AT) and increasing doses of isoproterenol (IsoP) (0.1, 1, 10, and 100 μg kg) were injected into animals. Right (RV) and left ventricles (LV) were removed to calculate Fulton's ratio (LV + septum (S) to RV weights) and to assess mRNA expression level of β1- and β2-adrenoceptors, muscarinic m1 and m2 receptors, and vascular endothelial growth factor (VEGF). Resting HR was significantly lower in rats than in pikas and increased after AT injection only in rats. IsoP injection induced a significant increase in HR in rat for all doses, which was systematically greater than in pikas. In pikas HR was slightly increased only after the two highest concentrations of IsoP. Fulton's ratio was greater in rats compared with pikas but the LV + S adjusted for body weight was greater in pikas. Pikas showed lower β1-adrenoceptors and muscarinic m2 receptors mRNA expression but larger VEGF mRNA expression than rats both in RV and LV. These results suggest that pikas have a lower maximal HR compared with rats certainly due to a decrease in β-adrenergic and muscarinic receptors mRNA expression. However, the LV hypertrophy probably led to an increase in stroke volume to maintain cardiac output in response to the cold and hypoxic environment. Blackwell Publishing Ltd 2013-07 2013-07-18 /pmc/articles/PMC3831927/ /pubmed/24303117 http://dx.doi.org/10.1002/phy2.32 Text en © 2013 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society http://creativecommons.org/licenses/by/2.5/ Re-use of this article is permitted in accordance with the Creative Commons Deed, Attribution 2.5, which does not permit commercial exploitation.
spellingShingle Original Research
Pichon, Aurélien
Zhenzhong, Bai
Marchant, Dominique
Jin, Guoen
Voituron, Nicolas
Haixia, Yun
Favret, Fabrice
Richalet, Jean-Paul
Ge, Ri-Li
Cardiac adaptation to high altitude in the plateau pika (Ochotona curzoniae)
title Cardiac adaptation to high altitude in the plateau pika (Ochotona curzoniae)
title_full Cardiac adaptation to high altitude in the plateau pika (Ochotona curzoniae)
title_fullStr Cardiac adaptation to high altitude in the plateau pika (Ochotona curzoniae)
title_full_unstemmed Cardiac adaptation to high altitude in the plateau pika (Ochotona curzoniae)
title_short Cardiac adaptation to high altitude in the plateau pika (Ochotona curzoniae)
title_sort cardiac adaptation to high altitude in the plateau pika (ochotona curzoniae)
topic Original Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3831927/
https://www.ncbi.nlm.nih.gov/pubmed/24303117
http://dx.doi.org/10.1002/phy2.32
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