Investigating glycogenosis type III patients with multi-parametric functional NMR imaging and spectroscopy.
Debranching enzyme deficiency (Glycogen storage disease (GSD) type III) causes progressive muscle wasting myopathy. A comprehensive nuclear magnetic resonance study involving spectroscopy (NMRS) and imaging (NMRI) evaluated status and function of calf muscles in 18 GSDIII patients. At rest, (31)P NMRS showed elevated pH and accumulation of anomalous phosphomonoesters, (13)C NMRS quantified excess glycogen accumulation and NMRI demonstrated progressive fat replacement that paralleled muscle weakness. Multi-parametric functional NMR, performed at recovery from a single bout of aerobic exercise, simultaneously assessed oxidative phosphorylation from (31)P NMRS, muscle perfusion and BOLD, a marker of blood oxygenation, from arterial spin labeled NMRI, and oxygen uptake from deoxymyoglobin proton NMRS. While blocked glycogenolysis caused inadequate substrate supply to the mitochondria, combined measurements suggested that altered perfusion was also responsible for impaired post-exercise phosphocreatine recovery and could contribute to exercise intolerance in GSDIII. These non-invasive investigations provide new indices to quantify the progression of GSDIII.
Wary
Claire
C
Institute of Myology, Paris, France. c.wary@institut-myologie.org
Nadaj-Pakleza
Aleksandra
A
Laforêt
Pascal
P
Claeys
Kristl G
KG
Carlier
Robert
R
Monnet
Aurélien
A
Fleury
Servanne
S
Baligand
Céline
C
Eymard
Bruno
B
Labrune
Philippe
P
Carlier
Pierre G
PG
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D004578:Electron Spin Resonance Spectroscopy; D004734:Energy Metabolism / Q000502:physiology; D015444:Exercise / Q000502:physiology; D005260:Female; D006003:Glycogen / Q000378:metabolism; D006010:Glycogen Storage Disease Type III / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D008931:Mitochondria, Muscle / Q000378:metabolism; D018482:Muscle, Skeletal / Q000098:blood supply / Q000378:metabolism / Q000473:pathology; D009211:Myoglobin / Q000378:metabolism; D010101:Oxygen Consumption / Q000502:physiology; D010758:Phosphorus / Q000378:metabolism; D012039:Regional Blood Flow; D055815:Young Adult
D009211:Myoglobin; C055547:deoxymyoglobin; D010758:Phosphorus; D006003:Glycogen