title: Diversity in levels of intracellular total creatine and triglycerides in human skeletal muscles observed by (1)H-MRS.
abstract: We used (1)H-magnetic resonance spectroscopy to noninvasively determine total creatine (TCr), choline-containing compounds (Cho), and intracellular (IT) and extracellular (between-muscle fibers) triglycerides (ET) in three human skeletal muscles. Subjects' (n = 15 men) TCr concentrations in soleus [Sol; 100.2 +/- 8.3 (SE) mmol/kg dry wt] were lower (P < 0.05) than those in gastrocnemius (Gast; 125.3 +/- 9.2 mmol/kg dry wt) and tibialis anterior (TA; 123. 7 +/- 8.8 mmol/kg dry wt). The Cho levels in Sol (35.8 +/- 3.6 mmol/kg dry wt) and Gast (28.5 +/- 3.5 mmol/kg dry wt) were higher (P < 0.001 and P < 0.01, respectively) compared with TA (13.6 +/- 2. 4 mmol/kg dry wt). The IT values were found to be 44.8 +/- 4.6 and 36.5 +/- 4.2 mmol/kg dry wt in Sol and Gast, respectively. The IT values of TA (24.5 +/- 4.5 mmol/kg dry wt) were lower than those of Sol (P < 0.01) and Gast (P < 0.05). There were no differences in ET [116.0 +/- 11.2 (Sol), 119.1 +/- 18.5 (Gast), and 91.4 +/- 19.2 mmol/kg dry wt (TA)]. It is proposed that the differences in metabolite levels may be due to the differences in fiber-type composition and deposition of metabolites due to the adaptation of different muscles during locomotion.
authors.affiliation: The Robert Steiner Magnetic Resonance Unit, Imperial College School of Medicine, Hammersmith Hospital, London W12 0HS, United Kingdom. j.rico-sanz@proton.uab.es
authors.forename: J
authors.initials: J
authors.lastname: Rico-Sanz
authors.forename: E L
authors.initials: EL
authors.lastname: Thomas
authors.forename: G
authors.initials: G
authors.lastname: Jenkinson
authors.forename: S
authors.initials: S
authors.lastname: Mierisová
authors.forename: R
authors.initials: R
authors.lastname: Iles
authors.forename: J D
authors.initials: JD
authors.lastname: Bell
mesh_terms: D000328:Adult; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism*; D005110:Extracellular Space / Q000378:metabolism; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism*; D007866:Leg; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism*; D011522:Protons; D014280:Triglycerides / Q000378:metabolism*
chemical_list: D011522:Protons; D014280:Triglycerides; D003401:Creatine; D002794:Choline