Increased blood-oxygen binding affinity in Tibetan and Han Chinese residents at 4200 m.
Exp Physiol
; 99(12): 1624-35, 2014 Dec 01.
Article
em En
| MEDLINE
| ID: mdl-25172885
ABSTRACT
High-altitude natives are challenged by hypoxia, and a potential compensatory mechanism could be reduced blood oxygen-binding affinity (P50), as seen in several high-altitude mammalian species. In 21 Qinghai Tibetan and nine Han Chinese men, all resident at 4200 m, standard P50 was calculated from measurements of arterial PO2 and forehead oximeter oxygen saturation, which was validated in a separate examination of 13 healthy subjects residing at sea level. In both Tibetans and Han Chinese, standard P50 was 24.5 ± 1.4 and 24.5 ± 2.0 mmHg, respectively, and was lower than in the sea-level subjects (26.2 ± 0.6 mmHg, P < 0.01). There was no relationship between P50 and haemoglobin concentration (the latter ranging from 15.2 to 22.9 g dl(-1) in Tibetans). During peak exercise, P50 was not associated with alveolar-arterial PO2 difference or peak O2 uptake per kilogram. There appears to be no apparent benefit of a lower P50 in this adult high-altitude Tibetan population.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oxigênio
/
Consumo de Oxigênio
/
Altitude
/
Hipóxia
Limite:
Adolescent
/
Adult
/
Humans
/
Male
País/Região como assunto:
Asia
Idioma:
En
Revista:
Exp Physiol
Assunto da revista:
FISIOLOGIA
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
Estados Unidos