Accuracy of 1H and 31P MRS analyses of lactate in skeletal muscle.
As the end product of anaerobic metabolism and a source of H(+), lactic acid is important in metabolism and pH regulation. Several methods have been introduced to calculate changes in the lactate anion (Lac(-)) concentration in exercising skeletal muscle from information derived from the (31)P spectrum. Alternatively, Lac-may be observed directly with (1)H MRS. Both (1)H and (31)P spectroscopy have potential problems, which could prevent accurate determination of [Lac(-)]. It is demonstrated that quantitatively accurate (1)H MRS measurements of changes in [Lac(-)] due to exercise are possible in isolated muscle. In general, calculation by (31)P MRS overestimates Lac-production. An analysis is presented of possible sources of errors in the (1)H and (31)P MRS methods.
Hsu
A C
AC
Biomedical Magnetic Resonance Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
Dawson
M J
MJ
D000818:Animals; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007424:Intracellular Fluid / Q000378:metabolism; D019344:Lactic Acid / Q000032:analysis* / Q000378:metabolism; D008274:Magnesium / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000737:chemistry* / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism; D010725:Phosphocreatine / Q000378:metabolism; D010759:Phosphorus Isotopes / Q000032:analysis; D005082:Physical Exertion / Q000502:physiology; D011188:Potassium / Q000378:metabolism; D011522:Protons; D011894:Rana pipiens; D015203:Reproducibility of Results
D010710:Phosphates; D010759:Phosphorus Isotopes; D011522:Protons; D010725:Phosphocreatine; D019344:Lactic Acid; D008274:Magnesium; D011188:Potassium