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Siebenmann C, Roche J, Schlittler M, Simpson LL, Stembridge M. Regulation of haemoglobin concentration at high altitude. J Physiol 2023. [PMID: 38051656 DOI: 10.1113/jp284578] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 11/21/2023] [Indexed: 12/07/2023] Open
Abstract
Lowlanders sojourning for more than 1 day at high altitude (HA) experience a reduction in plasma volume (PV) that increases haemoglobin concentration and thus restores arterial oxygen content. If the sojourn extends over weeks, an expansion of total red cell volume (RCV) occurs and contributes to the haemoconcentration. While the reduction in PV was classically attributed to an increased diuretic fluid loss, recent studies support fluid redistribution, rather than loss, as the underlying mechanism. The fluid redistribution is presumably driven by a disappearance of proteins from the circulation and the resulting reduction in oncotic pressure exerted by the plasma, although the fate of the disappearing proteins remains unclear. The RCV expansion is the result of an accelerated erythropoietic activity secondary to enhanced renal erythropoietin release, but a contribution of other mechanisms cannot be excluded. After return from HA, intravascular volumes return to normal values and the normalisation of RCV might involve selective destruction of newly formed erythrocytes, although this explanation has been strongly challenged by recent studies. In contrast to acclimatised lowlanders, native highlanders originating from the Tibetan and the Ethiopian plateaus present with a normal or only mildly elevated haemoglobin concentration. Genetic adaptations blunting the erythropoietic response to HA exposure have been proposed as an explanation for the absence of more pronounced haemoconcentration in these populations, but new evidence also supports a contribution of a larger than expected PV. The functional significance of the relatively low haemoglobin concentration in Tibetan and Ethiopian highlanders is incompletely understood and warrants further investigation.
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Affiliation(s)
| | - Johanna Roche
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy
| | - Maja Schlittler
- AO Research Institute Davos, Regenerative Orthopaedics Program, Davos, Switzerland
| | - Lydia L Simpson
- Department of Sport Science, Division of Performance Physiology and Prevention, Universität Innsbruck, Innsbruck, Austria
| | - Mike Stembridge
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
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Bothe TL, Pilz N, Patzak A, Opatz OS. Bridging the gap: The dichotomy between measurement and reality in physiological research. Acta Physiol (Oxf) 2023; 238:e14015. [PMID: 37354109 DOI: 10.1111/apha.14015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 06/14/2023] [Indexed: 06/26/2023]
Affiliation(s)
- T L Bothe
- Institute of Physiology, Center for Space Medicine and Extreme Environments Berlin, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - N Pilz
- Institute of Translational Physiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - A Patzak
- Institute of Translational Physiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - O S Opatz
- Institute of Physiology, Center for Space Medicine and Extreme Environments Berlin, Charité - Universitätsmedizin Berlin, Berlin, Germany
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Simionato G, Rabe A, Gallego-Murillo JS, van der Zwaan C, Hoogendijk AJ, van den Biggelaar M, Minetti G, Bogdanova A, Mairbäurl H, Wagner C, Kaestner L, van den Akker E. In Vitro Erythropoiesis at Different pO 2 Induces Adaptations That Are Independent of Prior Systemic Exposure to Hypoxia. Cells 2022; 11:cells11071082. [PMID: 35406648 PMCID: PMC8997720 DOI: 10.3390/cells11071082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 03/20/2022] [Accepted: 03/22/2022] [Indexed: 12/23/2022] Open
Abstract
Hypoxia is associated with increased erythropoietin (EPO) release to drive erythropoiesis. At high altitude, EPO levels first increase and then decrease, although erythropoiesis remains elevated at a stable level. The roles of hypoxia and related EPO adjustments are not fully understood, which has contributed to the formulation of the theory of neocytolysis. We aimed to evaluate the role of oxygen exclusively on erythropoiesis, comparing in vitro erythroid differentiation performed at atmospheric oxygen, a lower oxygen concentration (three percent oxygen) and with cultures of erythroid precursors isolated from peripheral blood after a 19-day sojourn at high altitude (3450 m). Results highlight an accelerated erythroid maturation at low oxygen and more concave morphology of reticulocytes. No differences in deformability were observed in the formed reticulocytes in the tested conditions. Moreover, hematopoietic stem and progenitor cells isolated from blood affected by hypoxia at high altitude did not result in different erythroid development, suggesting no retention of a high-altitude signature but rather an immediate adaptation to oxygen concentration. This adaptation was observed during in vitro erythropoiesis at three percent oxygen by a significantly increased glycolytic metabolic profile. These hypoxia-induced effects on in vitro erythropoiesis fail to provide an intrinsic explanation of the concept of neocytolysis.
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Affiliation(s)
- Greta Simionato
- Department of Experimental Physics, University Campus, Building E2.6, Saarland University, 66123 Saarbrücken, Germany; (A.R.); (C.W.); (L.K.)
- Department of Experimental Surgery, Campus University Hospital, Building 65, Saarland University, 66421 Homburg, Germany
- Correspondence: (G.S.); (E.v.d.A.)
| | - Antonia Rabe
- Department of Experimental Physics, University Campus, Building E2.6, Saarland University, 66123 Saarbrücken, Germany; (A.R.); (C.W.); (L.K.)
| | - Joan Sebastián Gallego-Murillo
- Sanquin Research, Landsteiner Laboratory, Department of Hematopoiesis, Amsterdam UMC, University of Amsterdam, 1066 CX Amsterdam, The Netherlands;
- Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, 2629 HZ Delft, The Netherlands
| | - Carmen van der Zwaan
- Sanquin Research, Landsteiner Laboratory, Department of Molecular Hematology, Amsterdam UMC, University of Amsterdam, 1066 CX Amsterdam, The Netherlands; (C.v.d.Z.); (A.J.H.); (M.v.d.B.)
| | - Arie Johan Hoogendijk
- Sanquin Research, Landsteiner Laboratory, Department of Molecular Hematology, Amsterdam UMC, University of Amsterdam, 1066 CX Amsterdam, The Netherlands; (C.v.d.Z.); (A.J.H.); (M.v.d.B.)
| | - Maartje van den Biggelaar
- Sanquin Research, Landsteiner Laboratory, Department of Molecular Hematology, Amsterdam UMC, University of Amsterdam, 1066 CX Amsterdam, The Netherlands; (C.v.d.Z.); (A.J.H.); (M.v.d.B.)
| | - Giampaolo Minetti
- Department of Biology and Biotechnology “L. Spallanzani”, Laboratories of Biochemistry, University of Pavia, I-27100 Pavia, Italy;
| | - Anna Bogdanova
- Red Blood Cell Research Group, Institute of Veterinary Physiology, University of Zurich, CH-8057 Zurich, Switzerland;
| | - Heimo Mairbäurl
- University Hospital Heidelberg, Medical Clinic VII, Sports Medicine, 69120 Heidelberg, Germany;
- Translational Lung Research Centre Heidelberg (TLRC), Part of the German Centre for Lung Research (DZL), 69120 Heidelberg, Germany
- Translational Pneumology, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Christian Wagner
- Department of Experimental Physics, University Campus, Building E2.6, Saarland University, 66123 Saarbrücken, Germany; (A.R.); (C.W.); (L.K.)
- Physics and Materials Science Research Unit, University of Luxembourg, L-1511 Luxembourg City, Luxembourg
| | - Lars Kaestner
- Department of Experimental Physics, University Campus, Building E2.6, Saarland University, 66123 Saarbrücken, Germany; (A.R.); (C.W.); (L.K.)
- Theoretical Medicine and Biosciences, Campus University Hospital, Building 61.4, Saarland University, 66421 Homburg, Germany
| | - Emile van den Akker
- Sanquin Research, Landsteiner Laboratory, Department of Hematopoiesis, Amsterdam UMC, University of Amsterdam, 1066 CX Amsterdam, The Netherlands;
- Correspondence: (G.S.); (E.v.d.A.)
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