N-acetyl-beta-D-glucosaminidase (NAG) and alanine aminopeptidase (AAP) excretion after acute administration of acetaminophen, salsalate and aspirin in rats.

The present study was performed to compare renal injury induced by high acute doses of both the nonacetylated salicylate, salsalate (SSA) and the acetylated salicylate, aspirin (ASA). As a marker of renal injury, urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG) and alanine aminopeptidase (AAP) were measured after oral administration of 600 mg/kg of each drug. Other tests to detect renal injury were also performed. Serum salicylic levels after SSA or ASA were determined in a different experiment. Acetaminophen (APAP) was used as a standard of renal toxicity. Both drugs increase NAG and to a greater extent, AAP excretion. Proteinuria and polyuria appear after both drugs. Changes in urinary sodium and potassium were also shown. Our results support the view that both acetylated and non-acetylated salicylates induce renal injury at toxicological doses.