title: The effect of 3-methylhistidine in food on its urinary excretion in man.
abstract: 1. To establish whether 3-methylhistidine in food is quantitatively excreted in the urine, five normal adults on a vegetarian diet were given known amounts of 3-methylhistidine in meat or fish. The mean cumulative 5-day increment in 3-methylhistidine excretion in non-hydrolysed urine accounted for an average of 90% of the 3-methylhistidine given during the first 3 days of this period. 2. To define the variation in urinary 3-methylhistidine on a constant mixed intake, the daily 3-methylhistidine excretion was measured for 6 days in four patients on a metabolic "balance" diet. The mean daily variation was less than 10%. 3. The results show that under the conditions of this study the increase in urinary 3-methylhistidine above basal levels can be quantitatively accounted for by the 3-methylhistidine content of additional food; in subjects on a constant diet it should be possible to detect relatively small changes in 3-methylhistidine excretion.
mesh_terms: D000328:Adult; D004032:Diet; D014676:Diet, Vegetarian; D005260:Female; D006639:Histidine / Q000031:analogs & derivatives*; D006801:Humans; D008297:Male; D008460:Meat / Q000032:analysis; D008762:Methylhistidines / Q000032:analysis / Q000652:urine*
chemical_list: D008762:Methylhistidines; D006639:Histidine