Interrelation of 31P-MRS metabolism measurements in resting and exercised quadriceps muscle of overweight-to-obese sedentary individuals.
Phosphorus magnetic resonance spectroscopy ((31)P-MRS) enables the non-invasive evaluation of muscle metabolism. Resting Pi-to-ATP flux can be assessed through magnetization transfer (MT) techniques, and maximal oxidative flux (Q(max)) can be calculated by monitoring of phosphocreatine (PCr) recovery after exercise. In this study, the muscle metabolism parameters of 13 overweight-to-obese sedentary individuals were measured with both MT and dynamic PCr recovery measurements, and the interrelation between these measurements was investigated. In the dynamic experiments, knee extensions were performed at a workload of 30% of maximal voluntary capacity, and the consecutive PCr recovery was measured in a quadriceps muscle with a time resolution of 2 s with non-localized (31)P-MRS at 3 T. Resting skeletal muscle metabolism was assessed through MT measurements of the same muscle group at 7 T. Significant linear correlations between the Q(max) and the MT parameters k(ATP) (r = 0.77, P = 0.002) and F(ATP) (r = 0.62, P = 0.023) were found in the study population. This would imply that the MT technique can possibly be used as an alternative method to assess muscle metabolism when necessary (e.g. in individuals after stroke or in uncooperative patients).
MR Centre of Excellence, Department of Radiology, Medical University of Vienna, Vienna, Austria; Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovak Republic.
Ladislav
L
Valkovič
Barbara
B
Ukropcová
Marek
M
Chmelík
Miroslav
M
Baláž
Wolfgang
W
Bogner
Albrecht Ingo
AI
Schmid
Ivan
I
Frollo
Erika
E
Zemková
Iwar
I
Klimeš
Jozef
J
Ukropec
Siegfried
S
Trattnig
Martin
M
Krššák
D000255:Adenosine Triphosphate / Q000378:metabolism; D000328:Adult; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000503:physiopathology*; D010084:Oxidation-Reduction; D010725:Phosphocreatine / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism; D010759:Phosphorus Isotopes; D052097:Quadriceps Muscle / Q000503:physiopathology*; D012146:Rest / Q000502:physiology*; D057185:Sedentary Behavior; D013997:Time Factors; D055815:Young Adult
D010759:Phosphorus Isotopes; D010725:Phosphocreatine; D010758:Phosphorus; D000255:Adenosine Triphosphate
31P-MRS; PCr recovery; magnetization transfer; muscle metabolism; obesity