ABSTRACT
Objective To study on the measurement of glycyl-proline dipeptidyl aminopeptidase (GPDA) in urine and its clinical application. Methods GPDA in urine was measured by continuously monitoring method using substrate. The assay conditions and interference factors were investigated. GPDA activities in urine specimens from 334 healthy persons, 55 diabetes mellitus patients and 36 hypertension patients were measured. The differences between the kidney injured and non-kidney injured groups were analyzed. Results The linearity of the method was up to 350 U/L. The intra CV and inter CV were 1.27% and 1.33% respectively. The GPDA activity in urine specimen was stable for 7 days at 4℃. There was no interference of bilirubin, glucose, vitamins, dimethylbiguanide and gliben-clamide. No significant interference was found by hemoglobin less than 500 mg/L. GPDA level in urine specimens of 334 healthy persons were (12.9?4.2) U/g?Cr. The GPDA levels of diabetes mellitus and hypertension groups combined with kidney injured were obviously higher than that of the control group and the non-kidney injured group ( P