title: Age dependence of human gastrocnemius Mg2+: fitting 31P-NMR spectra using quantum mechanics-based prior knowledge.
abstract: The age dependence of human gastrocnemius Mg2+ concentration is demonstrated. To quantitate Mg2+ concentration, an original and accurate fitting algorithm using quantum mechanics-based prior knowledge is detailed. In a group of 28 volunteers (14 females) in the age range 5-80 years, pH, PCr/ATP and Pi/ATP values in the gastrocnemius were 7.02 +/- 0.02 pH, 4.16 +/- 0.33 and 0.13 +/- 0.02, respectively and independent of age and sex. By contrast, intracellular Mg2+ concentration (mM) decreased linearly (p < 0.05) with age (Mg2+ = 0.7803 +/- 0.0247-0.0027 +/- 0.0005 * age). No difference was found between sexes. From these results, it follows that care must be taken when comparing muscle Mg2+ data from subjects of different age. The hypothesis can be put forward that during aging insufficient intake and/or increased depletion of Mg2+ (e.g., intestinal hypoabsorption or urinary leakage) may affect the musculoskeletal system.
authors.affiliation: Departments of Physiology and Radiology, Faculty of Medicine, University of Geneva, Geneva, Switzerland. Tiziano.Binzoni@medecine.unige.ch
authors.forename: T
authors.initials: T
authors.lastname: Binzoni
authors.forename: L
authors.initials: L
authors.lastname: Ngo
authors.forename: M
authors.initials: M
authors.lastname: Janssen
authors.forename: E
authors.initials: E
authors.lastname: Hiltbrand
authors.forename: S
authors.initials: S
authors.lastname: Bianchi
authors.forename: P
authors.initials: P
authors.lastname: Cerretelli
authors.forename: D
authors.initials: D
authors.lastname: Graveron-Demilly
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D002648:Child; D002675:Child, Preschool; D003198:Computer Simulation; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000378:metabolism* / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009010:Monte Carlo Method; D018482:Muscle, Skeletal / Q000378:metabolism*; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D010710:Phosphates / Q000378:metabolism; D010725:Phosphocreatine / Q000378:metabolism; D010758:Phosphorus; D011789:Quantum Theory
chemical_list: D010710:Phosphates; D010725:Phosphocreatine; D010758:Phosphorus; D000255:Adenosine Triphosphate; D008274:Magnesium