ABSTRACT

One of lyzozomal enzymes N-Acetyl-Beta-D-glucosaminidase (NAG), is a sensitive parameter of renal tubular injury. In order to to determine a confidential and easily applicable method we have plan to measure and compare the results of NAG activities with two different substrates namely p-nitrophenyl-N-acetyl-B-D-glucosaminide (PNP-NAG) and m-cresolsulfon-phtaleinyl-N-B-D-glu-cosaminide (MCP-NAG) .

We measured urinary NAG levels using PNP-NAG and MCP-NAG substrates in 40 healty persons, and in 40 renal failure patients. We also tested the effect of gel filtration on PNP-NAG method.

The urinary NAG levels measured by two different substrates were 27.5 u/L and 16.5 u/L in chronic renal failure group, 5.66 U/L and 3.62 U/L in control group. The differences between two groups were significant (p<0.001).

The measurement of urinary NAG levels using PNP-NAG substrate is an easy, effica-cious and cost effective method and the measurment range is wider comparing with MCP-NAG. This method may take part in the determination and management of renal tubular injury.

Keywords: Urinary N-acetyl-D-glucosaminidase, Tubular Injury, PNG-NAG, MCP, NAG