URINE AND SERUM LEUCINE AMINOPEPTIDASE, N-ACETYL-BETA-GLUCOSAMINIDASE AND GAMMA-GLUTAMYL-TRANSFERASE TRANSPEPTIDASE ACTIVITIES IN DIABETICS WITH AND WITHOUT NEPHROPATHY

Abstract

Urinary and serum activities of leucine aminopeptidase (LAP), N-acetyl-.beta.-glucosaminidase (ABG) and .gamma.-glutamyl transpeptidase (GGPT) were determined in 4 groups: control subjects with normal oral glucose tolerance test and normal renal function; latent diabetics and elevated oral glucose tolerance test and diabetic parents; overt diabetics; and diabetics with slight nephropathy, exemplified by elevated creatinine levels and decreased creatinine clearance. No clear differences were found in the urinary GGTP and serum enzyme activities. Urinary LAP activity was significantly increased in groups 2, 3 and 4, and urinary ABG activity in groups 3 and 4. Since the rise in urinary LAP activity was less consistent than that in ABG, the appearance of the latter enzyme in urine most likely results from tubular damage and may serve as a sensitive indicator of early diabetic kidney disease.