Abstract
Little is known of conditions which influence the stability of urinary enzymes upon storage in the bladder at 37°C. Using a continuous flow system simulatingin vivo conditions, we studied the influence of the pH of urine on the stability of two renal parenchymal enzymes N—Acetyl—β—D—Glucosaminidase (2—acetamido—2—deoxy—β—D—glucoside acetamidodeoxy glucohydrolase, NAG, EC 3.2.1.30) and L—Alanine aminopeptidase (Aminopeptidase N, AAP, EC 3.4.11.2). This continuous flow model that we have described can be employed to study the influence of pH on the stability of any renal enzyme excreted in urine. We also studied thein vitro effects of varying concentrations of low molecular weight regulatory metabolites such as urea, creatinine and uric acid and of some drugs excreted in urine, on the assay of these two enzymes. Urinary pH, urea content and some antibiotics seem to influence measured urinary NAG and AAP activities and we therefore express the need for caution before diagnostic interpretation of the urinary enzyme activities are made.
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Krishna, K.S., Kanagasabapathy, A.S. Study of some factors affecting stability of N-acetyl-β-D-glucosaminidase and aminopeptidase N in urine at 37°C. Indian J Clin Biochem 6, 17–25 (1991). https://doi.org/10.1007/BF02864960
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DOI: https://doi.org/10.1007/BF02864960