Flow cytometric analysis of the direct toxic effects of paraquat on cultured MDCK cells

✍ Scribed by Kazunobu Yamagami; Mineo Matsubara; Yasuhide Kitazawa; Naoshi Takeyama; Takaya Tanaka; Keiji Kawamoto

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 563 KB
• Volume: 14
• Category: Article
• ISSN: 0260-437X
• DOI: 10.1002/jat.2550140302

✦ Synopsis

We used flow cytometry to assess the cell cycle kinetics of cultured Maden Darby canine kidney cells after exposure to paraquat, Fluorescein diacetate fluorescence was used as a marker of cell viability, while bromodeoxyuridine incorporation was detected with a monoclonal antibody and propidium iodide staining to assess DNA synthesis. Flow cytometry was performed immediately, 48 h and % h after exposure to paraquat for 24 h. Lactate dehydrogenase release was also measured to determine the extent of cytolysis. Flow cytometry of paraquat-treated cells showed a marked increase of the S phase population immediately after exposure, at a time when there was no increase of lactate dehydrogenase release. In contrast, the cell cycle profile returned towards normal at 48 and % h after paraquat exposure, but lactate dehydrogenase release increased. These findings indicate that paraquat arrested cells in the S phase and that inhibition of DNA synthesis by this agent appeared to influence cell viability because S phase block occurred before cytolysis. In addition, this method proved useful for assessing the effects of paraquat on DNA synthesis by cultured cells.