PHOSPHORUS NUCLEAR-MAGNETIC-RESONANCE SPECTROSCOPY - IN-VIVO MAGNESIUM MEASUREMENTS IN THE SKELETAL-MUSCLE OF NORMAL SUBJECTS

P-31 nuclear magnetic resonance spectroscopy was used to study the ske letal muscle of 33 normal males and 32 females, Free intracellular mag nesium levels and the ratios of the phosphorus metabolites were determ ined. Males had significantly lower free magnesium levels (499.8 mu M +/- 26.3 mu M vs, 530.7 mu M +/- 36.0 mu M, P = 0.001, d.f. = 63, anal ysis of variance), The free magnesium level (r(s) = -0.5431, P = 0.001 ) and the phosphocreatine/inorganic phosphate ratio in males (r(s) = - 0.4102, P = 0.018), and the phosphocreatine/inorganic phosphate ratio in females (r(s) = -0.4759, P = 0.009) fell with the increasing Minnes ota Heart Health Program Questionnaire score.