Hemoglobin mass and intravascular volume kinetics during and after exposure to 3,454 m altitude.
2015 (English)In: Journal of applied physiology, ISSN 8750-7587, E-ISSN 1522-1601, Vol. 119, no 10Article in journal (Refereed) Published
High altitude (HA) exposure facilitates a rapid contraction of plasma volume (PV) and a slower occurring expansion of hemoglobin mass (Hbmass). The kinetics of the Hbmass expansion has never been examined by multiple repeated measurements and this was our primary study aim. The second aim was to investigate the mechanisms mediating the PV contraction. Nine healthy, normally-trained sea-level (SL) residents (8 males, 1 female) sojourned for 28 days at 3,454 m. Hbmass was measured and PV estimated by carbon monoxide re-breathing at SL, on every fourth day at HA, and one and two weeks upon return to SL. Four weeks at HA increased Hbmass by 5.26 % (range 2.5 - 11.1 %; p<0.001). The individual Hbmass increases commenced with up to 12 days delay and reached a maximal rate of 4.04 ± 1.02 g.d-1 after 14.9 ± 5.2 days. The probability for Hbmass to plateau increased steeply after 20-24 days. Upon return to SL Hbmass decayed by -2.46 ± 2.3 g.d-1, reaching values similar to baseline after two weeks. PV, aldosterone concentration and renin activity were reduced at HA (p<0.001) while the total circulating protein mass remained unaffected. In summary the Hbmass response to HA exposure followed a sigmoidal pattern with a delayed onset and a plateau after ~3 weeks. The decay rate of Hbmass upon descent to SL did not indicate major changes in the rate of erythrolysis. Moreover, our data supports that PV contraction at HA is regulated by the renin-angiotensin-aldosterone axis and not by changes in oncotic pressure.
Place, publisher, year, edition, pages
2015. Vol. 119, no 10
Blood, erythropoietin, hypoxia, oxygen, plasma volume
IdentifiersURN: urn:nbn:se:kth:diva-173621DOI: 10.1152/japplphysiol.01121.2014ISI: 000365905900020ScopusID: 2-s2.0-84947215920OAI: oai:DiVA.org:kth-173621DiVA: diva2:853971
QC 201509222015-09-152015-09-152016-01-07Bibliographically approved