Alterations in cerebral blood flow and cerebrovascular reactivity during 14 days at 5050 m.
Brain blood flow increases during the first week of living at high altitude. We do not understand completely what causes the increase or how the factors that regulate brain blood flow are affected by the high-altitude environment. Our results show that the balance of oxygen (O(2)) and carbon dioxide (CO(2)) pressures in arterial blood explains 40% of the change in brain blood flow upon arrival at high altitude (5050 m). We also show that blood vessels in the brain respond to increases and decreases in CO(2) differently at high altitude compared to sea level, and that this can affect breathing responses as well. These results help us to better understand the regulation of brain blood flow at high altitude and are also relevant to diseases that are accompanied by reductions in the pressure of oxygen in the blood.
Department of Physiology, University of Otago, Dunedin, New Zealand. sam.lucas@otago.ac.nz
Samuel J E
SJ
Lucas
Keith R
KR
Burgess
Kate N
KN
Thomas
Joseph
J
Donnelly
Karen C
KC
Peebles
Rebekah A I
RA
Lucas
Jui-Lin
JL
Fan
James D
JD
Cotter
Rishi
R
Basnyat
Philip N
PN
Ainslie
D000064:Acclimatization / Q000502:physiology*; D000328:Adult; D000531:Altitude; D001783:Blood Flow Velocity / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D002245:Carbon Dioxide / Q000097:blood; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006935:Hypercapnia / Q000503:physiopathology; D016857:Hypocapnia / Q000503:physiopathology; D000860:Hypoxia / Q000503:physiopathology; D008297:Male; D020768:Middle Cerebral Artery / Q000502:physiology; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D011659:Pulmonary Gas Exchange / Q000502:physiology; D012123:Pulmonary Ventilation / Q000502:physiology; D017534:Radial Artery / Q000378:metabolism; D014655:Vascular Resistance / Q000502:physiology; D055815:Young Adult
D002245:Carbon Dioxide; D010100:Oxygen