Su, J;
Logan, CC;
Hughes, AD;
Parker, KH;
Dhutia, NM;
Danielsen, CC;
Simonsen, U;
(2018)
Impact of chronic hypoxia on proximal pulmonary artery wave propagation and mechanical properties in rats.
American Journal of Physiology. Heart and Circulatory Physiology
, 314
(6)
H1264-H1278.
10.1152/ajpheart.00695.2017.
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Abstract
Arterial stiffness and wave reflection are important components of the ventricular afterload. Therefore, we aimed to assess the arterial wave characteristics and mechanical properties of the proximal pulmonary arteries (PAs) in the hypoxic pulmonary hypertensive rat model. After 21 days in normoxic or hypoxic chambers (24 animals/group), animals underwent transthoracic echocardiography and PA catheterization with a dual-tipped pressure and Doppler flow sensor wire. Wave intensity analysis was performed. Artery rings obtained from the pulmonary trunk, right and left PAs, and aorta were subjected to a tensile test to rupture. Collagen and elastin content were determined. In hypoxic rats, proximal PA wall thickness, collagen content, tensile strength per unit collagen, maximal elastic modulus, and wall viscosity increased, whereas the elastin-to-collagen ratio and arterial distensibility decreased. Arterial pulse wave velocity was also increased, and the increase was more prominent in vivo than ex vivo. Wave intensity was similar in hypoxic and normoxic animals with negligible wave reflection. In contrast, the aortic maximal elastic modulus remained unchanged, whereas wall viscosity decreased. In conclusion, there was no evidence of altered arterial wave propagation in proximal PAs of hypoxic rats while the extracellular matrix protein composition was altered and collagen tensile strength increased. This was accompanied by altered mechanical properties in vivo and ex vivo. NEW & NOTEWORTHY: In rats exposed to chronic hypoxia, we have shown that pulse wave velocity in the proximal pulmonary arteries increased and pressure dependence of the pulse wave velocity was steeper in vivo than ex vivo leading to a more prominent increase in vivo.
| Type: | Article |
|---|---|
| Title: | Impact of chronic hypoxia on proximal pulmonary artery wave propagation and mechanical properties in rats |
| Location: | United States |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1152/ajpheart.00695.2017 |
| Publisher version: | https://doi.org/10.1152/ajpheart.00695.2017 |
| Language: | English |
| Additional information: | © 2018 American Physiological Society. All rights reserved. This is an Open Access article licensed under the Creative Commons Attribution CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/). |
| Keywords: | arterial stiffness, extracellular matrix, hypoxia, pulmonary hypertension, pulse wave velocity |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Population Health Sciences > Institute of Cardiovascular Science UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Population Health Sciences > Institute of Cardiovascular Science > Population Science and Experimental Medicine |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10047959 |
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