名称:
Thionate versus Oxon: Comparison of Stability, Uptake, and Cell Toxicity of (14CH3O)2-Labeled Methyl Parathion and Methyl Paraoxon with SH-SY5Y Cells
摘要:
The stability, hydrolysis, and uptake of the organophosphates methyl parathion and methyl paraoxon were investigated in SH-SY5Y cells. The stabilities of ((CH3O)-C-14)(2)-methyl parathion (C-14-MPS) and ((CH3O)-C-14)2-methyl paraoxon (C-14-MPO) at 1 mu M in culture media had similar half-lives of 91.7 and 101.9 h, respectively. However, 100 mu M MPO caused >95% cytotoxicity at 24 h, whereas 100 mu M MPS caused 4-5% cytotoxicity at 24 h (approximate to 60% cytotoxicity at 48 h). Greater radioactivity was detected inside cells treated with MPO as compared to MPS, although >80% of the total MPO uptake was primarily dimethyl phosphate (DMP). Maximum uptake was reached after 48 h of C-14-MPS or (CMPO)-C-14 exposure with total uptakes of 1.19 and 1.76 nM/10(6) cells for MPS and MPO, respectively. The amounts of MPS and MPO detected in the cytosol after 48 h of exposure time were 0.54 and 0.37 nM/10(6) cells, respectively.