Divergent respiratory and cardiovascular responses to hypoxia in bar-headed geese and Andean birds.

Autor:	Lague SL; Department of Zoology, University of British Columbia, 4200-6270 University Boulevard, Vancouver, BC, Canada, V6T 1Z4 lague@zoology.ubc.ca., Chua B; Department of Zoology, University of British Columbia, 4200-6270 University Boulevard, Vancouver, BC, Canada, V6T 1Z4., Alza L; Department of Biology and Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, Coral Gables, FL 33146, USA.; Institute of Arctic Biology and University of Alaska Museum, University of Alaska Fairbanks, Fairbanks, AK 99775, USA.; Department of Ornithology, Centro de Ornitología y Biodiversidad, Lima, Peru., Scott GR; Department of Biology, McMaster University, 1280 Main Street West, Hamilton, ON, Canada, L8S 4K1., Frappell PB; Institute of Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7001, Australia., Zhong Y; Institute of Biodiversity Science and Institute of High Altitude Medicine, Tibet University, Lhasa 850000, China.; School of Life Sciences, Fudan University, Shanghai 200433, China., Farrell AP; Department of Zoology, University of British Columbia, 4200-6270 University Boulevard, Vancouver, BC, Canada, V6T 1Z4.; Faculty of Land and Food Systems, University of British Columbia, 2357 Main Mall, Vancouver, BC, Canada, V6T 1Z4., McCracken KG; Department of Biology and Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, Coral Gables, FL 33146, USA.; Institute of Arctic Biology and University of Alaska Museum, University of Alaska Fairbanks, Fairbanks, AK 99775, USA., Wang Y; Department of Biology, Queen's University, Kingston, ON, Canada, K7L 3N6., Milsom WK; Department of Zoology, University of British Columbia, 4200-6270 University Boulevard, Vancouver, BC, Canada, V6T 1Z4.
Jazyk:	angličtina
Zdroj:	The Journal of experimental biology [J Exp Biol] 2017 Nov 15; Vol. 220 (Pt 22), pp. 4186-4194.
DOI:	10.1242/jeb.168799
Abstrakt:	Many high-altitude vertebrates have evolved increased capacities in their oxygen transport cascade (ventilation, pulmonary diffusion, circulation and tissue diffusion), enhancing oxygen transfer from the atmosphere to mitochondria. However, the extent of interspecies variation in the control processes that dictate hypoxia responses remains largely unknown. We compared the metabolic, cardiovascular and respiratory responses to progressive decreases in inspired oxygen levels of bar-headed geese ( Anser indicus ), birds that biannually migrate across the Himalayan mountains, with those of Andean geese ( Chloephaga melanoptera ) and crested ducks ( Lophonetta specularioides ), lifelong residents of the high Andes. We show that Andean geese and crested ducks have evolved fundamentally different mechanisms for maintaining oxygen supply during low oxygen (hypoxia) from those of bar-headed geese. Bar-headed geese respond to hypoxia with robust increases in ventilation and heart rate, whereas Andean species increase lung oxygen extraction and cardiac stroke volume. We propose that transient high-altitude performance has favoured the evolution of robust convective oxygen transport recruitment in hypoxia, whereas life-long high-altitude residency has favoured the evolution of structural enhancements to the lungs and heart that increase lung diffusion and stroke volume. Competing Interests: Competing interestsThe authors declare no competing or financial interests. (© 2017. Published by The Company of Biologists Ltd.)
Databáze:	MEDLINE
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