The Mechanisms Of Danofloxacin Induced Cell Cycle Arrest In LLC-Pk1

Fluoroquinolones ?FQs? were widely used in human medicine and veterinary clinic as a well-tolerated class of bactericidal antibiotics. The renal injury case of FQs was rarely, but research showed that FQs may induce a series of renal renal dysfunction in improper use, such as interstitial between granuloma nephritis, acute tubular necrosis and other adverse reactions. So renal injury is a potential adverse, but the pathogenesis was not clearly. The results found that oxidative stress is major factor of kidney damage induced by FQs, but the exact mechanism of injury is unclear.Objective:This study was investigate the influence of danofloxacin to LLC-PK1, Through the change of poptosis and cell cycle to evaluate the nephrotoxicity mechanism after oxidative stress induced by danofloxacin in LLC-PK1 cells. To provides scientific basis for guiding clinical therapy and prevention toxicity of Veterinary, and provides an important theoretical guidance for further study of FQs Kidney Injury Mechanism. Methods:The growth inhibitory effect, the change of O???, H₂O₂ was determined by WST-1, DHE and Amplex UltraRed method, respectively. Mitochondrial membrane potential was examined by Rhodamine123. The cell cycle and apoptosis were measured by Flow cytometry. The expression change of related gene were measured by RT-PCR. Results:Danofloxacin induced a concentration-dependent suppress in the proliferation of LLC-PK1. The O???, H₂O₂ production were also increased and caused cell cycle arrest, but the mitochondrial membrane potential and apoptosis of cells was no significantly change. When 100 ?mol/L danofloxacin treated with LLC-PK1 cells, cycle was arrested in G2 phase. These results indicated that cell didn't significant damage and the increased of ROS was in the range of self-repair. However 400 ?mol/L danofloxacin could induce a reversible G1 phase cell cycle arrest. The Cyclin inhibition protein p53, p21, p27 mRNA expression were significantly increased. The oxidative stress induced by danofloxacin in LLC-PK1 cells could aslo be repaired. Conclusion :Danofloxacin in the concentration range of 400 ?mol/L could induce cell cycle arrest in LLC-Pkl cells within 24 h, but did not induce cell apoptosis because cellular damage could be repaired.