title: N tau-methyl histidine excretion by poultry: not all species excrete N tau-methyl histidine quantitatively.
abstract: The rate of elimination of administered N tau-[14CH3]methyl histidine was used to assess the validity of N tau-methyl histidine excretion as an index of muscle protein breakdown in poultry. Broiler chicks (2-3 and 4-5 weeks old), laying hens, adult quail (Coturnix coturnix japonica), adult cockerels and turkey poults (2-4 weeks old) were tested. All except the turkey poults showed quantitative recoveries of N tau-[14CH3]methyl histidine within 1 week. Turkeys showed a different pattern of N tau-[14CH3]methyl histidine output; the mean total recovery after 14 d was less than 50% of the injected dose. The majority of the label remaining after this time was found in breast muscle. All birds tested excreted N tau-methyl histidine unchanged, although a small amount sometimes appeared as another metabolite. No significant oxidation of N tau-[14CH3]methyl histidine by broiler chicks turkey poults or adult quail was found. The results show that excretion of N tau-methyl histidine is a useful measure of muscle protein breakdown in the domestic fowl and quail but not in turkeys.
mesh_terms: D000818:Animals; D002645:Chickens / Q000378:metabolism; D003370:Coturnix / Q000378:metabolism; D005243:Feces / Q000032:analysis; D005260:Female; D006639:Histidine / Q000031:analogs & derivatives* / Q000378:metabolism; D008297:Male; D008762:Methylhistidines / Q000378:metabolism*; D009124:Muscle Proteins / Q000378:metabolism; D009132:Muscles / Q000378:metabolism; D011200:Poultry / Q000378:metabolism*; D013045:Species Specificity; D014018:Tissue Distribution; D014422:Turkeys / Q000378:metabolism
chemical_list: D008762:Methylhistidines; D009124:Muscle Proteins; D006639:Histidine; C028118:3-methylhistidine