title: 3-methylhistidine excretion in myotonic dystrophy.
abstract: 3-Methylhistidine (3-MH) excretion reflects the rate of muscle protein catabolism, since 3-MH occurs almost exclusively in muscle actin and myosin and is not reutilized or catabolized. We studied 3-MH excretion in 9 patients with myotonic dystrophy, 8 normals, and 10 disease controls with Duchenne dystrophy and other disorders. 3-MH excretion was expressed relative to muscle mass as determined by both urinary creatinine and total body potassium (40K method). Absolute 3-MH excretion was decreased in myotonic dystrophy patients but was normal when related to muscle mass. The finding of normal 3-MH excretion in myotonic dystrophy suggests that the muscle wasting in this disorder results from impaired anabolic processes rather than accelerated muscle destruction.
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003401:Creatine / Q000652:urine; D003404:Creatinine / Q000652:urine; D004032:Diet; D006639:Histidine / Q000031:analogs & derivatives*; D006760:Hospitalization; D006801:Humans; D008297:Male; D008460:Meat; D008762:Methylhistidines / Q000652:urine*; D008875:Middle Aged; D009124:Muscle Proteins / Q000378:metabolism; D009136:Muscular Dystrophies / Q000378:metabolism / Q000652:urine; D009223:Myotonic Dystrophy / Q000378:metabolism / Q000652:urine*; D011188:Potassium / Q000032:analysis
chemical_list: D008762:Methylhistidines; D009124:Muscle Proteins; D006639:Histidine; D003404:Creatinine; D003401:Creatine; D011188:Potassium