Trial reportThe Journal of physiology2006
Erythrocytes and the regulation of human skeletal muscle blood flow and oxygen delivery: role of erythrocyte count and oxygenation state of haemoglobin.
Trial report in The Journal of physiology, 2006. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 63 papers, 3 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
63 citing papers in PubMed, 3 syntheses or guidelines pooled it, 132 citations in OpenAlex.
- The Methodological Quality of Studies Investigating the Acute Effects of Exercise During Hypoxia Over the Past 40 years: A Systematic Review.Frontiers in physiology · 2022Pooled it
- Effects of Repeated-Sprint Training in Hypoxia on Sea-Level Performance: A Meta-Analysis.Sports medicine (Auckland, N.Z.) · 2017Pooled it
- Effects of Exercise Training in Hypoxia Versus Normoxia on Vascular Health.Sports medicine (Auckland, N.Z.) · 2016Pooled it
- Cardiorespiratory and oxygenation responses in iron-deficient anemic women during whole-body exercise under moderate hypoxia.European journal of applied physiology · 2026Trial
- Plasma Nucleotide Dynamics during Exercise and Recovery in Highly Trained Athletes and Recreationally Active Individuals.BioMed research international · 2018Trial
- Decreased arterial PO2, not O2 content, increases blood flow through intrapulmonary arteriovenous anastomoses at rest.The Journal of physiology · 2016Trial
- Venous occlusion plethysmography versus Doppler ultrasound in the assessment of leg blood flow during calf exercise.European journal of applied physiology · 2011Trial
- Haematological parameters and muscle oxygen saturation in elite male speed skaters during a 2-min time trial.European journal of applied physiology · 2026Article
- The heart, a secondary organ in the control of blood circulation.Experimental physiology · 2025Review
- Adrenergic control of skeletal muscle blood flow during chronic hypoxia in healthy males.American journal of physiology. Regulatory, integrative and comparative physiology · 2023Article
- Variability in Resting-State Functional Magnetic Resonance Imaging: The Effect of Body Mass, Blood Pressure, Hematocrit, and Glycated Hemoglobin on Hemodynamic and Neuronal Parameters.Brain connectivity · 2022Article
- Effect of adrenaline on serum mid-regional pro-atrial natriuretic peptide and central blood volume.Experimental physiology · 2022Article
- A century of exercise physiology: key concepts in muscle cell volume regulation.European journal of applied physiology · 2022Review
- Review
- Dose of Bicarbonate to Maintain Plasma pH During Maximal Ergometer Rowing and Consequence for Plasma Volume.Frontiers in physiology · 2022Article
- Monitoring adaptation of skin tissue oxygenation during cycling ergometer exercise by frequency-domain diffuse optical spectroscopy.Biomedical optics express · 2021Article
- Exercise Testing, Physical Training and Fatigue in Patients with Mitochondrial Myopathy Related to mtDNA Mutations.Journal of clinical medicine · 2021Review
- Exercise Heat Acclimation With Dehydration Does Not Affect Vascular and Cardiac Volumes or Systemic Hemodynamics During Endurance Exercise.Frontiers in physiology · 2021Article
- The physiology of rowing with perspective on training and health.European journal of applied physiology · 2020Review
- Dehydration reduces stroke volume and cardiac output during exercise because of impaired cardiac filling and venous return, not left ventricular function.Physiological reports · 2020Article
3 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors at 3 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Blood flow to dynamically contracting myocytes is regulated to match O(2) delivery to metabolic demand. The red blood cell (RBC) itself functions as an O(2) sensor, contributing to the control of O(2) delivery by releasing the vasodilators ATP and S-nitrosohaemoglobin with the offloading of O(2) from the haemoglobin molecule. Whether RBC number is sensed remains unknown. To investigate the role of RBC number, in isolation and in combination with alterations in blood oxygenation, on muscle and systemic perfusion, we measured local and central haemodynamics during one-legged knee-extensor exercise ( approximately 50% peak power) in 10 healthy males under conditions of normocythaemia (control), anaemia, anaemia + plasma volume expansion (PVX), anaemia + PVX + hypoxia, polycythaemia, polycythaemia + hyperoxia and polycythaemia + hypoxia, which changed either RBC count alone or both RBC count and oxyhaemoglobin. Leg blood flow (LBF), cardiac output (Q) and vascular conductance did not change with either anaemia or polycythaemia alone. However, LBF increased with anaemia + PVX (28 +/- 4%) and anaemia + PVX + hypoxia (46 +/- 6%) and decreased with polycythaemia + hyperoxia (18 +/- 5%). LBF and Q with anaemia + PVX + hypoxia (8.0 +/- 0.5 and 15.8 +/- 0.7 l min(-1), respectively) equalled those during maximal knee-extensor exercise. Collectively, LBF and vascular conductance were intimately related to leg arterial-venous (a-v) O(2) difference (r(2)= 0.89-0.93; P < 0.001), suggesting a pivotal role of blood O(2) gradients in muscle microcirculatory control. The systemic circulation accommodated to the changes in muscle perfusion. Our results indicate that, when coping with severe haematological challenges, local regulation of skeletal muscle blood flow and O(2) delivery primarily senses alterations in the oxygenation state of haemoglobin and, to a lesser extent, alterations in the number of RBCs and haemoglobin molecules.
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What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.