Microvascular tissue oxygenation and oxidative metabolism changes in the pedicled latissimus dorsi muscle during graded hypoxia: correlation between near infrared and 31P nuclear magnetic resonance spectroscopy.

Abstract

BACKGROUND:

In this study, the microvascular tissue oxygenation and oxidative muscle metabolism during graded hypoxia and reoxygenation were examined in a rabbit model by near-infrared (NIR) spectroscopy and correlated with high-energy phosphates measured by (31)P nuclear magnetic resonance (NMR) spectroscopy.

MATERIALS AND METHODS:

Graded hypoxia was performed in a New Zealand rabbit model (n = 20, 2.0 ± 0.4 kg) by a stepwise reduction of the fraction of inspired oxygen (FiO(2)) from 0.3 to 0.05 (intervention group versus control group). Recovery and reoxygenation were achieved using FiO(2) of 0.3. A noninvasive NIR spectroscopy sensor and NMR probe was positioned on the surface of the prepared pedicled latissimus dorsi muscle. Microvascular tissue oxygenation (oxyhemoglobin, HbO(2); deoxyhemoglobin, HHb) and redox state of cytochrome oxidase (CytOx) were measured by NIR spectroscopy and correlated with standard values of oxidative muscle metabolism (phosphocreatine, PCr; adenosine triphosphate, ATP) measured by time-resolved (31)P NMR spectroscopy (4.7T).

RESULTS:

Significant correlation was found between PCr and HbO(2) (r = 0.85, P < 0.001) and HHb (r = -0.75, P < 0.001). β-ATP levels correlated significantly with CytOx (r = 0.87, P < 0.001).

CONCLUSIONS:

The data suggest that changes in high-energy phosphates (PCr- and ATP-levels) correlate closely with microvascular tissue oxygenation (HbO(2), HHb, CytOx) measured by NIR spectroscopy.

• Authors: Dirk Troitzsch, Rainer Moosdorf, Sebastian Vogt
• Journal: The Journal of surgical research (J Surg Res) Vol. 176 Issue 1 Pg. 337-42 (Jul 2012) ISSN: 1095-8673 [Electronic] United States
• PMID: 21705019 (Publication Type: Comparative Study, Journal Article)
• Copyright: Copyright © 2012 Elsevier Inc. All rights reserved.

Chemical References

• Hemoglobins
• Oxyhemoglobins
• Phosphorus Isotopes
• Phosphocreatine
• Adenosine Triphosphate
• deoxyhemoglobin
• Electron Transport Complex IV
• Oxygen

Topics

• Adenosine Triphosphate (metabolism)
• Animals
• Electron Transport Complex IV (metabolism)
• Hemoglobins (metabolism)
• Hypoxia (metabolism)
• Magnetic Resonance Spectroscopy (methods)
• Male
• Microvessels (metabolism)
• Models, Animal
• Muscle, Skeletal (metabolism)
• Oxidation-Reduction
• Oxygen (metabolism)
• Oxyhemoglobins (metabolism)
• Phosphocreatine (metabolism)
• Phosphorus Isotopes
• Rabbits
• Spectroscopy, Near-Infrared (methods)