title: Determination of urinary carbamylaspartate and dihydro-orotate in normal subjects and in patients with hereditary orotic aciduria.
abstract: An isotope dilution assay for urinary dihydro-orotic acid and carbamylaspartic acid (CAA) has been developed which has been shown to yield accurate measurements for these pyrimidine precurosrs. Dihydro-orotic acid could not be detected in 24-hour urine specimens from 10 normal adults and 7 normal children, or in specimens from 2 children with hereditary orotic aciduria Type I. Small amounts (approximately 10 mumole per 24 hours) of carbamylaspartic acid are excreted in normal urine, and there was a modest elevation in CAA excretion in the 2 patients with hereditary orotic aciduria.
mesh_terms: D000328:Adult; D000592:Amino Acid Metabolism, Inborn Errors; D001224:Aspartic Acid / Q000652:urine*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008661:Metabolism, Inborn Errors; D009963:Orotic Acid / Q000652:urine*; D011743:Pyrimidines / Q000096:biosynthesis; D011865:Radioisotope Dilution Technique
chemical_list: D011743:Pyrimidines; D001224:Aspartic Acid; D009963:Orotic Acid