Aminoglycoside-induced viability in cultured PtK1 proximal tubular cell lines

The cell viability after aminoglycoside administration was evaluated by the determination of adenosine triphosphate (ATP) level and trypan blue exclusion of cultured PtK1 tubular cells. The assay in tubular cells was performed using luciferin-luciferase determined by a chemiluminator. The data are expressed as relative light units per milligram tissue protein. The standard curve of ATP showed a linearity from 0.5 to 2.5 mg/ml ATP as determined by the chemiluminator. The incubation time was steady for ATP production during 90 min after addition of ligand. The optimal incubation time was 60 min. The ATP production in PtK1 cells showed linearity within 10(3) to 5 x 10(6) cells in 200 microliters buffer. Although the magnitude of ATP production in Ptk1 cells was correlated with the cell viability as defined by trypan blue exclusion, the reproducibility of the former was better than that of the latter. The cell viability after application of aminoglycoside showed a decrement in a dose-dependent fashion. Our ATP assay is an excellent tool for determining the cell viability of renal proximal tubules in cases with tubular damage after administration of aminoglycoside antibiotics.