Details

Autor(en) / Beteiligte

• Lague, Sabine L
• Chua, Beverly
• Alza, Luis
• Scott, Graham R
• Frappell, Peter B
• Zhong, Yang
• Farrell, Anthony P
• McCracken, Kevin G
• Wang, Yuxiang
• Milsom, William K

Titel

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

Ist Teil von

• Journal of experimental biology, 2017-11, Vol.220 (Pt 22), p.4186-4194

Ort / Verlag

England: The Company of Biologists Ltd

Erscheinungsjahr

2017

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• 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 ( ), birds that biannually migrate across the Himalayan mountains, with those of Andean geese ( ) and crested ducks ( ), 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.