3-Hydroxyproline content of normal urine.
Values for total 3-hydroxyproline and 4-hydroxyproline were obtained from 24-h urine specimens of 18 healthy human subjects of both sexes, whose ages ranged from the first to the sixth decade in age. Urinary 3-hydroxyproline levels, not earlier described to our knowledge, were determined by an isotope-dilution method requiring considerable purification and utilizing the amino acid analyzer for final measurement. 3-Hydroxyproline averaged 3% of the corresponding 4-hydroxyproline in individual urine samples. Like 4-hydroxyproline, 3-hydroxyproline excretion is increased in the second decade, and there is generally good correlation between the two values in individual urines. A hydroxyprolinemic subject excreting greatly elevated 4-hydroxyproline levels did not excrete excessive 3-hydroxyproline, consistent with independent catabolic pathways for the two compounds. 3-Hydroxyproline appears to be selectively excreted relative to 4-hydroxyproline when compared with the probable total body content of each amino acid. Possible explanations are: a more rapid turnover of basement membrane collagen than interstitial collagen or, alternatively, relatively greater resistance to the proteolytic cleavage of peptides containing 3-hydroxyproline.
D000293:Adolescent; D000328:Adult; D000592:Amino Acid Metabolism, Inborn Errors / Q000652:urine; D002648:Child; D005260:Female; D006801:Humans; D006909:Hydroxyproline / Q000097:blood / Q000652:urine*; D008297:Male; D008722:Methods; D008875:Middle Aged; D012016:Reference Values
D006909:Hydroxyproline