Effect of dimethoate on cytotoxicity and apoptosis in mouse skeletal muscle cells

  Objective   To investigate the cellular mechanism of muscular weakness in the Intermediate Myasthenia Syndrome(IMS)following acute organophosphate poisoning.Cytotoxicity of dimetheoate and its effects on the apoptosis were studied in mouse skeletal muscle cells.

  Methods   Skeletal muscle cells were incubated withe 35 350 and 3 500μmol/Lconcentrations of dimetheoate for 3 h or incubated for 3, 9, 24h withe 350μmol/Lconcentrations.The morphological changes of cultured cells were observed; cell viability were assessed withe typan blue dye and apoptotic cells were detected by flow cytometer (FCM); the activity of lactic dehydrogenase(LDH)was measured by colorimetry metheod.

  Results   There were significantly increased in a dose-dependent and time2dependent manner(r=0.821, r=0.955, P < 0.01), and the cell viability also decreased, and apoptotic rate were increased afterexposure of dimetheoate.

  Conclusion   Dimetheoate has significantly cytotoxicity and may induce apoptosis on skeletal muscle cell in vitro.These effects may play an important role in the etiology of IMS.