Urinary N-acetyl-beta-d-glucosaminidase isoenzymes as biomarker of renal dysfunction caused by cadmium in a general population

N-Acetyl-beta-D-glucosaminidase (NAG) and its isoenzymes in urine have been studied in a population group residing in a polluted area in China, The ar ea studied was contaminated by industrial wastewater from a nearby smelter that discharged cadmium-polluted wastewater into a river used for the irrig ation of rice fields, Cadmium concentrations in rice were 3.70, 0.51, and 0 .07 mg/kg for the highly and moderately polluted areas and the control area , respectively, Cadmium concentrations in urine exceeded 5 mu g/liter in th e majority of subjects in the most highly polluted area, There was a marked dose-dependent increase in NAG and NAG B content of urine related both to urinary cadmium and to the calculated cadmium uptake, It is concluded that urinary NAG and its isoenzymes could serve as a sensitive biomarker of rena l dysfunction in cadmium-exposed populations. The mechanisms underlying the increase in NAG and its isoenzymes after cadmium exposure need to be studi ed further. (C) 1999 Academic Press.