Objective: To study a detection method for drug early nephrotoxicity based on Madin-Darby canine kidney (MDCK) cells monolayer. Method: MDCK cells were cultured on microporous membrane to form a complete monolayer. Then the cells were treated with different drug concentration which had obviously inhibition on MDCK or not selected by MTT test. After 24 h

the cells were detected with fluorescein sodium permeability test and investigated by scanning electron microscope. At the same time

the activity of alkaline phosphatase (ALP)

γ-glutamyl transpeptidase(γ-GT) and lactate dehydrogenase (LDH) that secreted by both sides of the cell layer were also detected. Result: We choose three concentration of aristolochic acid(AA) to detect it's toxicity

they were 3.13

6.25

12.5 mg·L-1. And their inhibition on MDCK cell were-0.93%

0.93% and 24.30%. AA 3.13 mg·L-1 could not disrupt the integrity of cell monolayer

and fluorescein sodium also can not penetrate the monolayer. AA 6.25

12.5 mg·L-1 could obviously increase the permeation of fluorescein sodium after 30 min (P<0.05

P<0.1)

especially for AA 12.5 mg·L-1. In either side of the cell layer

there showed no difference with ALP or γ-GT secretion. However

AA 12.5 mg·L-1 could increase LDH leakage on both sides of monolayer evidently (P<0.05). In SEM detection

cells treated with AA 6.25

12.5 mg·L-1 emerged a large number of small spherical objects in surface

and the monolayer became incomplete. Conclusion: Based on MDCK monolayer

AA toxicity can be detected at the concentration which has no obviously inhibition on cells. It suggests that MDCK monolayer system established on microporous membrane could be used for early detection of drug nephrotoxicity.