Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1993-2-26
pubmed:abstractText
Cerebral blood flow increases with acute exposure to high altitude, but the effect of hypoxia on the cerebral circulation at rest and during exercise appears influenced by the duration of high-altitude exposure. To determine whether internal carotid artery flow velocity increased with exercise in long-term residents of high altitude and whether resting values and the response to exercise differed in lifelong vs. acclimatized newcomer male residents of high altitude, we studied 15 native Tibetan and 11 Han ("Chinese") 6 +/- 2-yr residents of Lhasa (3,658 m), Tibet Autonomous Region, China. Noninvasive Doppler ultrasound was used to measure internal carotid artery diameter, mean flow velocity, and, in combination, hemoglobin and arterial O2 saturation to assess cerebral O2 delivery. Tibetan and Han groups were similar in body size and resting internal carotid artery diameter, blood pressure, hemoglobin concentration, internal carotid artery mean flow velocity, and calculated cerebral O2 delivery. Submaximal exercise increased internal carotid artery mean flow velocity and cerebral O2 delivery in the Tibetan and Han subjects. At peak exercise, the Tibetans sustained the increase in flow velocity and cerebral O2 delivery, whereas the Hans did not. Across all exercise levels up to and including peak effort, the Tibetans demonstrated a greater increase in internal carotid artery flow velocity and cerebral O2 delivery relative to resting values than did the Hans. The greater cerebral O2 delivery was accompanied by increased peak exercise capacity in the Tibetan compared with the Han group. Our findings suggest that the cerebral blood flow response to exercise is maintained in Tibetan lifelong residents of high altitude.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
8750-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
73
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2638-42
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Internal carotid arterial flow velocity during exercise in Tibetan and Han residents of Lhasa (3,658 m).
pubmed:affiliation
Shanghai Institute of Physiology, China.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.