title: Quantitative importance of non-skeletal-muscle sources of N tau-methylhistidine in urine.
abstract: Direct measurement of N tau-methylhistidine turnover in skeletal muscle, skin and gastrointestinal muscle indicates that these three tissues contribute only 24.9, 6.8 and 9.8% of the total urinary excretion. Measurement of the decay rate of radioactively labelled N tau-methylhistidine in urine indicates that skeletal muscle accounts for 74.5% of the urinary excretion and this is probably an overestimate. These results suggest that the common assumption, that N tau-methylhistidine in urine originates almost entirely from skeletal muscle, may be wrong.
mesh_terms: D000818:Animals; D005260:Female; D006639:Histidine / Q000031:analogs & derivatives*; D007700:Kinetics; D008762:Methylhistidines / Q000378:metabolism* / Q000652:urine; D009130:Muscle, Smooth / Q000378:metabolism; D009132:Muscles / Q000378:metabolism*; D051381:Rats; D012867:Skin / Q000378:metabolism
chemical_list: D008762:Methylhistidines; D006639:Histidine