Evaluation of renal damage using urinary ATP analysis

It is reported that urinary ATP concentration analysis is useful for determining urinary tract infection and renal damage caused by drugs. By means of the firefly luciferin-luciferase method, we determined the reference value of urinary free ATP and evaluated the effects of urine sediments and conditions of storage. The reference value was established as 1.77 × 10 ^-10∼7.70 × 10^-9M using urine samples obtained from 63 outpatients who seemed to have no renal disease. There was no significant difference in ATP concentration between 33 males and 30 females. No significant changes were observed in 11 healthy volunteers during a 1-year period. Within-run reproducibility of ATP was satisfying (8.28% and 11.4% of coefficient value in low and high concentration samples, respectively). ATP concentration was significantly decreased after centrifugation (p < 0.05) and after filtration (p < 0.01). The amounts of the red blood cells (RBC) and white blood cells (WBC) in samples whose ATP concentration was decreased after centrifugation or filtration were significantly higher than those in samples whose concentration did not decrease (p < 0.05). Urine containing many RBCs and/or WBCs might show an artificially higher ATP concentration if no preparations has been performed. There were significant positive correlations between the ATP concentrations before and after refrigeration, but no correlations before and after freezing. It is concluded that the reference value of urinary free ATP concentration was 1.77 × 10^-10∼7.70 × 10^-9 M and that care is required in the estimation of urinary ATP concentrations in samples containing many sediments, especially with WBC and RBC.