OBJECTIVETo investigate whether tri-ortho-cresyl phosphate (TOCP) and organophosphate compound that could produce organophosphate-induced delayed neuropathy (OPIDN) in hen and other sensitive species, directly affect oligodendrocytes, the myelin-forming cell of the central nervous system.

METHODSThis was achieved by a combination of measurements of cell viability (MTT) cell pathological observation in the presence and absence of the compound cultured hen brain oligodendrocytes were prepared and treated with various concentrations of TOCP.

RESULTSIn a time-course experiment TOCP showed a cytotoxic effect to oligodendrocytes and led to the oligodendrocyte processes disintegrated and membranous blebs, cytoplasmic vacuolation following exposure time of 24 h or longer, it showed a dose-depended and time-depended manner cytotoxic effect to oligodendrocytes at dose levels of 0.5 approximately 1.5 microg/ml (1.35 approximately 4.05 mol/L) concentrations of TOCP for 24 - 72 h exposure. MTT experiment indicated that TOCP inhibited cell viability by dose-depended manner at dose levels of 0.5 approximately 1.5 microg/ml (1.35 approximately 4.05 mol/L) concentrations of TOCP for an 24 h exposure.

CONCLUSIONSTOCP is cytotoxic to oligodendrocytes and leads to the oligodendrocyte processes disintegrated and membranous blebs, vacuolar degeneration, which suggests that this oligodendrocyte degeneration may involve in the pathogenesis mechanism for OPIDN.