The influence of hemoconcentration on hypoxic pulmonary vasoconstriction in acute, prolonged and life-long hypoxemia

Published on Aug 27, 2021in American Journal of Physiology-heart and Circulatory Physiology3.864
· DOI :10.1152/AJPHEART.00357.2021
Mike Stembridge15
Estimated H-index: 15
(Cardiff Metropolitan University),
Ryan L. Hoiland20
Estimated H-index: 20
(UBC: University of British Columbia)
+ 12 AuthorsJames D. Anholm13
Estimated H-index: 13
(LLU: Loma Linda University)
Sources
Abstract
Haemoconcentration can influence hypoxic pulmonary vasoconstriction (HPV) via increased frictional force and vasoactive signalling from erythrocytes, but whether the balance of these mechanism is m...
📖 Papers frequently viewed together
7 Citations
2 Citations
1 Citations
References53
Newest
#1Michael M. Tymko (UBC: University of British Columbia)H-Index: 14
#2Ryan L. Hoiland (UBC: University of British Columbia)H-Index: 20
Last. Philip N. Ainslie (UBC: University of British Columbia)H-Index: 65
view all 23 authors...
NEW FINDINGS: What is the central question of this study? Herein, a methodological overview of our research team's (Global REACH) latest high altitude research expedition to Peru is provided. What is the main finding and its importance? The experimental objectives, expedition organization, measurements, and key cohort data are discussed. The select data presented in the current manuscript demonstrate the hematological differences between lowlanders and Andeans with and without excessive erythroc...
10 CitationsSource
#1Connor A. Howe (UBC: University of British Columbia)H-Index: 10
#2Philip N. Ainslie (UBC: University of British Columbia)H-Index: 65
Last. Ryan L. Hoiland (UBC: University of British Columbia)H-Index: 20
view all 15 authors...
Article published in Experimental Physiology on 13 August 2019 (online), available at: https://doi.org/10.1113/EP087663.
5 CitationsSource
#1Mike Stembridge (Cardiff Metropolitan University)H-Index: 15
#2Alexandra M. Williams (UBC: University of British Columbia)H-Index: 7
Last. Philip N. Ainslie (UBC: University of British Columbia)H-Index: 65
view all 9 authors...
In contrast to Andean natives, high-altitude Tibetans present with a lower hemoglobin concentration that correlates with reproductive success and exercise capacity. Decades of physiological and genomic research have assumed that the lower hemoglobin concentration in Himalayan natives results from a blunted erythropoietic response to hypoxia (i.e., no increase in total hemoglobin mass). In contrast, herein we test the hypothesis that the lower hemoglobin concentration is the result of greater pla...
20 CitationsSource
#1Joshua C. Tremblay (Queen's University)H-Index: 13
#2Ryan L. Hoiland (UBC: University of British Columbia)H-Index: 20
Last. Philip N. AinslieH-Index: 65
view all 16 authors...
Excessive erythrocytosis (EE; hemoglobin concentration [Hb] ≥21 g/dL in adult males) is associated with increased cardiovascular risk in highlander Andeans. We sought to quantify shear stress and a...
23 CitationsSource
#1Lydia L. Simpson (Bangor University)H-Index: 5
#2Stephen A. Busch (U of A: University of Alberta)H-Index: 5
Last. Jonathan P. Moore (Bangor University)H-Index: 14
view all 7 authors...
KEY POINTS: Hypoxia, a potent activator of the sympathetic nervous system, is known to increase muscle sympathetic nerve activity (MSNA) to the peripheral vasculature of native Lowlanders during sustained high altitude (HA) exposure. We show that the arterial baroreflex control of MSNA functions normally in healthy Lowlanders at HA, and that upward baroreflex resetting permits chronic activation of basal sympathetic vasomotor activity under this condition. The baroreflex MSNA operating point and...
26 CitationsSource
#1Mike Stembridge (Cardiff Metropolitan University)H-Index: 15
#2Philip N. Ainslie (UBC: University of British Columbia)H-Index: 65
Last. Rob E. Shave (Cardiff Metropolitan University)H-Index: 5
view all 9 authors...
KEY POINTS: We sought to determine the isolated and combined influence of hypovolaemia and hypoxic pulmonary vasoconstriction on the decrease in left ventricular (LV) function and maximal exercise capacity observed under hypobaric hypoxia. We performed echocardiography and maximal exercise tests at sea level (344 m), and following 5-10 days at the Barcroft Laboratory (3800 m; White Mountain, California) with and without (i) plasma volume expansion to sea level values and (ii) administration of t...
25 CitationsSource
#1Christopher K. Willie (UBC: University of British Columbia)H-Index: 21
#2Mike Stembridge (Cardiff Metropolitan University)H-Index: 15
Last. Philip N. Ainslie (UBC: University of British Columbia)H-Index: 65
view all 15 authors...
Article published in PLoS One available open access at https://doi.org/10.1371/journal.pone.0204660
14 CitationsSource
#1Rebecca Vanderpool (UA: University of Arizona)H-Index: 26
#2Robert Naeije (EUR: Erasmus University Rotterdam)H-Index: 92
The diagnosis and evaluation of severity of pulmonary vascular disease rests on the invasive determination of a pulmonary vascular resistance (PVR). It is often overlooked that PVR is linearly related to the viscosity of the blood, which in turn is curvilinearly related to hematocrit. We propose a correction diagram for patients with anemia or with polycythemia. Based on a distensibility model of the pulmonary circulation, we show that magnitude of hematocrit correction of PVR is increased in pr...
18 CitationsSource
#1Claire Maufrais (French Institute of Health and Medical Research)H-Index: 5
#2Thomas Rupp (French Institute of Health and Medical Research)H-Index: 22
Last. Guillaume WaltherH-Index: 21
view all 7 authors...
The aim of this study was to analyse the underlying mechanisms of left and right ventricular (LV and RV) functional alterations during several days in high-altitude hypoxia.Resting evaluations of LV and RV function and mechanics were assessed by Speckle Tracking Echocardiography on 11 subjects at sea level (SLPRE), 3 ± 2 h after helicopter transport to high altitude (D0), at day 2 (D2), day 4 (D4) and day 6 (D6) at 4350 m and 5 ± 2 h after return to sea level (SLPOST). Subjects experienced acute...
20 CitationsSource
#1Andrew M. Luks (UW: University of Washington)H-Index: 23
#2Denny Z. H. LevettH-Index: 27
Last. Erik R. Swenson (UW: University of Washington)H-Index: 47
view all 9 authors...
New Findings What is the central question of this study? Do the pulmonary vascular responses to hypoxia change during progressive exposure to high altitude and can alterations in these responses be related to changes in concentrations of circulating biomarkers that affect the pulmonary circulation? What is the main finding and its importance? In our field study with healthy volunteers, we demonstrate changes in pulmonary artery pressure suggestive of remodelling in the pulmonary circulation, but...
17 CitationsSource
Cited By0
Newest