Relationships between Fiber Composition and NMR Measurements in Human Skeletal Muscle

✍ Scribed by Hideyuki Takahashi; Shin-ya Kuno; Shigeru Katsuta; Hitoshi Shimojo; Kazumi Masuda; Hiroshi Yoshioka; Izumi Anno; Yuji Itai

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 539 KB
• Volume: 9
• Category: Article
• ISSN: 0952-3480
• DOI: 10.1002/(sici)1099-1492(199602)9:1<8::aid-nbm387>3.0.co;2-f

✦ Synopsis

The purpose of this study was to examine the relationships between the relative contents of phosphocreatine (PCr), inorganic phosphate (Pi), Fadenosine triphosphate (ATP), and transverse relaxation time (TJ with fiber composition, which determined histochemically in the human skeletal muscle. The vastus lateralis muscles of 28 volunteers were subjected to phosphorus nuclear magnetic resonance (31P NMR) spectroscopy, magnetic resonance imaging (MRI) and muscle biopsy. Muscle fibers were divided into type I and type I1 fibers using myosin ATPase stain. A wide range of fiber composition levels were observed in the subjects (27.3-74.6% type I fibers). The PCr/ATP, WATP and (PCr+Pi)/ATP ratios were positively related to the percentage of type I1 fibers (r =0.695,p < 0.001, r =0.429, p < 0.05 and r = 0.773, p < 0.001, respectively). There was no correlation between fiber composition and the PCrlPi ratio (r 0.127, n.s.) or intracellular pH (r=0.305, n.s.). Moreover, no correlation was found between T2 and fiber type (r=O.144, n.s.). These results suggest that "P NMR can detect the differences in relative content of phosphates between type I and type I1 fibers, thereby noninvasively evaluating fiber composition in human skeletal muscle.