Myoglobin content and oxygen diffusion: model analysis of horse and steer muscle.
Abstract: We test the hypothesis that myoglobin is important for O2 supply near the oxidative capacity of muscle. This hypothesis is evaluated with a simple model that incorporates the properties of heart and skeletal muscle tissue taken from steers and horses exercising at their maximum O2 consumption rate. These tissue samples allowed us to set the bounds on oxidative demand and O2 flux from red blood cells to the core of the muscle fiber, to estimate the blood and tissue capacities for O2 diffusion, and to define the capillary blood PO2 driving this O2 flux. A model combining blood convection with tissue diffusion indicates that O2 diffusion alone is insufficient to achieve the measured O2 fluxes in many samples. The myoglobin content of these fibers is significantly correlated with this O2 diffusion limitation and provides sufficient additional O2 flux to meet muscle O2 demand. The presence of myoglobin maintains the PO2 in the fiber core above anoxic levels for the majority of muscles. Thus myoglobin is critical to O2 supply at fluxes near the maximum and prevents anoxia by maintaining PO2 above levels needed to support mitochondrial function.
Publication Date: 1996-12-01 PubMed ID: 8997205DOI: 10.1152/ajpcell.1996.271.6.C2027Google Scholar: Lookup
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- Journal Article
- Research Support
- U.S. Gov't
- Non-P.H.S.
- Research Support
- U.S. Gov't
- P.H.S.
Summary
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The study tests the importance of myoglobin – a protein in heart and skeletal muscles – in supplying oxygen to muscles during high-intensity exercise in horses and steer.
Research Objective
The researchers aimed to examine the role of myoglobin in oxygen supply when the muscles are operating near their maximum oxidative capacity. They used steers and horses’ heart and skeletal muscle tissues at their maximum oxygen consumption rate for this exploration.
Methodology
- A simple model was developed that incorporated the properties of heart and skeletal muscle tissues obtained from steers and horses exerting to their maximum oxygen consumption capacity.
- The tissue samples allowed the researchers to establish the boundaries for oxidative demand and oxygen conduction from red blood cells to the core of the muscle fiber.
- The model also made it possible to estimate the capacities of blood and tissue for oxygen diffusion and to set the capillary blood partial pressure of oxygen (PO2) that drives this oxygen flow.
Findings
The model, that combined blood convection with tissue diffusion, suggested that oxygen diffusion alone is insufficient to achieve the measured oxygen fluxes in many samples.
- It was found that myoglobin content of these fibers was significantly correlated with this oxygen diffusion limitation. In other words, myoglobin presented additional oxygen flux, allowing muscles to meet their oxygen demand.
- Myoglobin was found to maintain the PO2 in the fiber core above levels that would result in full oxygen deprivation (anoxia) in most muscles. This means that the presence of myoglobin helps prevent anoxia by maintaining PO2 at levels that are required to support the functioning of mitochondria.
Conclusion
The research concludes by highlighting the crucial role of myoglobin in supplying muscle oxygen at almost maximum levels, and by keeping the PO2 in the muscle fiber core above anoxic levels, it effectively prevents anoxic conditions which could impact mitochondrial function detrimentally.
In summary, this research posits that myoglobin is critical for oxygen supply in muscles when they are functioning near their maximum capacity.
Cite This Article
APA
Conley KE, Jones C.
(1996).
Myoglobin content and oxygen diffusion: model analysis of horse and steer muscle.
Am J Physiol, 271(6 Pt 1), C2027-C2036.
https://doi.org/10.1152/ajpcell.1996.271.6.C2027 Publication
Researcher Affiliations
- Department of Radiology, University of Washington Medical Center, Seattle 98195-7115, USA.
MeSH Terms
- Animals
- Cattle
- Horses
- Models, Biological
- Muscle, Skeletal / metabolism
- Myoglobin / metabolism
- Oxygen / metabolism
- Oxygen Consumption
Grant Funding
- A6-10853 / PHS HHS
- AR-41928 / NIAMS NIH HHS
- HL-07059 / NHLBI NIH HHS
Citations
This article has been cited 7 times.- Poole DC, Musch TI. Capillary-Mitochondrial Oxygen Transport in Muscle: Paradigm Shifts. Function (Oxf) 2023;4(3):zqad013.
- Poole DC, Musch TI, Colburn TD. Oxygen flux from capillary to mitochondria: integration of contemporary discoveries. Eur J Appl Physiol 2022 Jan;122(1):7-28.
- Galluzzo M, Pennacchietti S, Rosano S, Comoglio PM, Michieli P. Prevention of hypoxia by myoglobin expression in human tumor cells promotes differentiation and inhibits metastasis. J Clin Invest 2009 Apr;119(4):865-75.
- Mänttäri S, Anttila K, Järvilehto M. Testosterone stimulates myoglobin expression in different muscles of the mouse. J Comp Physiol B 2008 Sep;178(7):899-907.
- Wang D, Kreutzer U, Chung Y, Jue T. Myoglobin and hemoglobin rotational diffusion in the cell. Biophys J 1997 Nov;73(5):2764-70.
- Schenkman KA, Ciesielski WA, Gernsheimer TB, Arakaki LSL. Myoglobin saturation as an intracellular indicator for transfusion need in oncology patients. Transfus Med 2025 Feb;35(1):68-74.
- Adepu KK, Anishkin A, Adams SH, Chintapalli SV. A versatile delivery vehicle for cellular oxygen and fuels or metabolic sensor? A review and perspective on the functions of myoglobin. Physiol Rev 2024 Oct 1;104(4):1611-1642.
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