Protection by glycerol of urinary L-alanine aminopeptidase activity from freezing and thawing inactivation.
L-Alanine aminopeptidase (AAP) and N-acetyl-beta-D-glucosaminidase (NAG) activities in urine are sensitive indicators of renal damage. However, urinary AAP loses its activity during storage in the frozen state. This study proposes a method for preventing the inactivation of AAP by adding glycerol to a final concentration of 10% to a urine sample before freezing and thawing. This study also showed that NAG is stable to freezing and thawing and is not affected by addition of glycerol.
D000118:Acetylglucosaminidase / Q000652:urine; D000818:Animals; D005615:Freezing; D005990:Glycerol; D006801:Humans; D007674:Kidney Diseases / Q000201:enzymology; D008297:Male; D009842:Oligopeptides / Q000652:urine*; D011489:Protein Denaturation / Q000187:drug effects; D051381:Rats; D013048:Specimen Handling
D009842:Oligopeptides; C029579:antiarrhythmic peptide; D000118:Acetylglucosaminidase; D005990:Glycerol