Quantification of myoglobin deoxygenation and intracellular partial pressure of O<sub>2</sub> during muscle contraction during haemoglobin‐free medium perfusion

Takakura, Hisashi; Masuda, Kouji; Hashimoto, Takeshi; Iwase, Satoshi; Jue, Thomas

doi:10.1113/expphysiol.2009.050344

Cited by 23 publications

(55 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While both b and X 0 were consistently above the line of identity (i.e., deoxy[Hb?Mb] values smaller than the corresponding oxy[Hb?Mb] for b, but greater for X 0 ), nonetheless there were strong correlations across the range of values (i.e., subjects with faster responses (smaller b and X 0 ) in one response also showed faster responses in the other). Grassi et al 2003;Koga et al 2007), following maximal 3 s contractions in the human forearm and during 120 s of 1 Hz twitch contractions at various intensities in the rat hindlimb preparation (Maguire et al 2007;Takakura et al 2010;Masuda et al 2010). In contrast, we found that the sigmoidal functions provided a better fit to NIRS data during PORH than the exponential function in 85% (34 of Mb] responses were initially best described as exponential in these two subjects).…”

Section: Resultscontrasting

confidence: 47%

Characterizing near-infrared spectroscopy responses to forearm post-occlusive reactive hyperemia in healthy subjects

2011

View full text Add to dashboard Cite

During post-occlusive reactive hyperemia (PORH) there is a temporary increase in the total hemoglobin + myoglobin (T[Hb+Mb]) signal as measured by near-infrared spectroscopy (NIRS). This transient increase predicts differences in the kinetic responses of deoxy[Hb+Mb] and oxy[Hb+Mb] during PORH. The purpose of this study was to determine whether sigmoidal (Gompertz or logistic) or exponential functions better describe these response curves during PORH. The fit of the three functions (exponential, Gompertz and logistic) to the NIRS responses, as determined from residual sum of squares, was compared using repeated measures ANOVA on Ranks. The Gompertz function provided a better fit to the oxy[Hb+Mb] response curve than did either the exponential or logistic function (χ (2) = 21.7, df = 2, p < 0.001). The logistic function provided a better fit for the deoxy[Hb+Mb] response (χ (2) = 22.9, df = 2, p < 0.001) than did either the Gompertz or exponential functions. For both NIRS signals, the better fitting sigmoidal functions fit the data well, with an average r value of 0.99 or greater. Adipose tissue thickness was correlated with parameters related to signal strength (amplitude, r = 0.86-0.89; baseline, r = 0.67-0.75; all p < 0.001) but was not related to kinetic parameters (time constant and inflection point; p > 0.05 for all comparisons). These results suggest that during PORH distinct sigmoidal mathematical functions best describe the responses of the oxy[Hb+Mb] (Gompertz) and deoxy[Hb+Mb] (logistic) as measured by NIRS. Further, differences in both the kinetic and amplitude aspects for the responses of oxy[Hb+Mb] and deoxy[Hb+Mb] predict the observed transient change in T[Hb+Mb]. Our methods provide a technique to evaluate and quantify NIRS responses during PORH, which may have clinical utility.

show abstract

Section: Resultscontrasting

confidence: 47%

Characterizing near-infrared spectroscopy responses to forearm post-occlusive reactive hyperemia in healthy subjects

2011

View full text Add to dashboard Cite

show abstract

“…; Takakura et al . ). Although Mb may play important roles in O 2 transport, Mb knockout mice remain viable, fertile and exhibit normal exercise capacity (Garry et al .…”

Section: Introductionmentioning

confidence: 97%

“…; Takakura et al . ), to regulate mitochondrial O 2 consumption in skeletal muscles. However, the mechanism still remains unclear.…”

Section: Introductionmentioning

confidence: 99%

Myoglobin and the regulation of mitochondrial respiratory chain complex IV

Yamada

Takakura

Jue

et al. 2015

The Journal of Physiology

Self Cite

View full text Add to dashboard Cite

Key pointsr Mitochondrial respiration is regulated by multiple elaborate mechanisms. r It has been shown that muscle specific O 2 binding protein, Myoglobin (Mb), is localized in mitochondria and interacts with respiratory chain complex IV, suggesting that Mb could be a factor that regulates mitochondrial respiration.r Here, we demonstrate that muscle mitochondrial respiration is improved by Mb overexpression via up-regulation of complex IV activity in cultured myoblasts; in contrast, suppression of Mb expression induces a decrease in complex IV activity and mitochondrial respiration compared with the overexpression model. r The present data are the first to show the biological significance of mitochondrial Mb as a potential modulator of mitochondrial respiratory capacity.Abstract Mitochondria are important organelles for metabolism, and their respiratory capacity is a primary factor in the regulation of energy expenditure. Deficiencies of cytochrome c oxidase complex IV, which reduces O 2 in mitochondria, are linked to several diseases, such as mitochondrial myopathy. Moreover, mitochondrial respiration in skeletal muscle tissue tends to be susceptible to complex IV activity. Recently, we showed that the muscle-specific protein myoglobin (Mb) interacts with complex IV. The precise roles of mitochondrial Mb remain unclear. Here, we demonstrate that Mb facilitates mitochondrial respiratory capacity in skeletal muscles. Although mitochondrial DNA copy numbers were not altered in Mb-overexpressing myotubes, O 2 consumption was greater in these myotubes than that in mock cells (Mock vs. Mb-Flag::GFP: state 4, 1.00 ± 0.09 vs.

show abstract

“…The diffusion gradients of several torr reported to occur in tissues under resting or low work rates are the result of methodological limitations and/or errors in interpretation. Takakura et al (59), for example, reported oxygen diffusion gradients of 9.8 torr in resting rat skeletal muscle. The experimental tissue was saline-perfused rat hindlimb, and the intracellular oxygen pressure was calculated from the fraction saturation of myoglobin, as measured by near-infrared spectroscopy.…”

Section: E508 Programming and Regulation Of Metabolic Homeostasismentioning

confidence: 99%

Programming and regulation of metabolic homeostasis

Wilson

2015

American Journal of Physiology-Endocrinology and Metabolism

View full text Add to dashboard Cite

Wilson DF. Programming and regulation of metabolic homeostasis. Am J Physiol Endocrinol Metab 308: E506 -E517, 2015. First published January 20, 2015 doi:10.1152 doi:10. /ajpendo.00544.2014dence is presented that the rate and equilibrium constants in mitochondrial oxidative phosphorylation set and maintain metabolic homeostasis in eukaryotic cells. These internal constants determine the energy state ([ATP]/[ADP][P i]), and the energy state maintains homeostasis through a bidirectional sensory/signaling control network that reaches every aspect of cellular metabolism. The energy state is maintained with high precision (to ϳ1 part in 10 10 ), and the control system can respond to transient changes in energy demand (ATP utilization) of more than 100 times the resting rate. Epigenetic and environmental factors are able to "fine-tune" the programmed set point over a narrow range to meet the special needs associated with cell differentiation and chronic changes in metabolic requirements. The result is robust across-platform control of metabolism, which is essential to cellular differentiation and the evolution of complex organisms. A model of oxidative phosphorylation is presented, for which the steady-state rate expression has been derived and computer programmed. The behavior of oxidative phosphorylation predicted by the model is shown to fit the experimental data available for isolated mitochondria as well as for cells and tissues. This includes measurements from several different mammalian tissues as well as from insect flight muscle and plants. The respiratory chain and oxidative phosphorylation is remarkably similar for all higher plants and animals. This is consistent with the efficient synthesis of ATP and precise control of metabolic homeostasis provided by oxidative phosphorylation being a key to cellular differentiation and the evolution of structures with specialized function. oxygen; oxidative phosphorylation; energy metabolism; oxygen pressure; metabolic control; mitochondria; respiratory control THOUSANDS OF DIFFERENT METABOLITES AND ENZYMES must work together if a cell is to survive and grow. In addition to the complex ensemble of reactions within individual cells, in organisms with extensive cellular differentiation, metabolism must support the robust cell-to-cell communication needed for different cell types to contribute to integrated function of the organism. DNA contains the blueprint needed to construct the parts of the ensemble, but in living cells metabolism has to constantly and rapidly respond to changes in the environment. These metabolic responses often occur in seconds, far faster than information encoded in the DNA can be read and implemented. Real-time control of metabolism requires a metabolic unit with intrinsic properties that drive it toward a particular metabolic condition (set point) and is connected to the rest of metabolism through a network of regulatory pathways that maintain that set point (65). To control the ensemble, this central control unit needs to have sensory input fr...

show abstract

Quantification of myoglobin deoxygenation and intracellular partial pressure of O₂ during muscle contraction during haemoglobin‐free medium perfusion

Cited by 23 publications

References 33 publications

Characterizing near-infrared spectroscopy responses to forearm post-occlusive reactive hyperemia in healthy subjects

Characterizing near-infrared spectroscopy responses to forearm post-occlusive reactive hyperemia in healthy subjects

Myoglobin and the regulation of mitochondrial respiratory chain complex IV

Programming and regulation of metabolic homeostasis

Contact Info

Product

Resources

About

Quantification of myoglobin deoxygenation and intracellular partial pressure of O2 during muscle contraction during haemoglobin‐free medium perfusion

Cited by 23 publications

References 33 publications

Characterizing near-infrared spectroscopy responses to forearm post-occlusive reactive hyperemia in healthy subjects

Characterizing near-infrared spectroscopy responses to forearm post-occlusive reactive hyperemia in healthy subjects

Myoglobin and the regulation of mitochondrial respiratory chain complex IV

Programming and regulation of metabolic homeostasis

Contact Info

Product

Resources

About

Quantification of myoglobin deoxygenation and intracellular partial pressure of O₂ during muscle contraction during haemoglobin‐free medium perfusion