Studies On The Toxicology Of Trichlorfon To Rat Cortical Neuron

To investigate the effect and mechanism of low concentration trichlorfon on rat cortical neuron, this study based on establishing the model of cortical neuron cultured in vitro which were obtained from the neonate Sprague-Dawley rats in 24h. The cell culture medium was exposured to trichlorfon of 0,5,20,80mg/L, and then observed the morphology of cortical neuron and evaluated the changes of short diameter of the cell body, neurite length, apoptosis rate, mitochondrial membrane potential, [Ca2+]i, content of ROS intra-cellular and activities of ATPase at different times.The results were as follows:①Exposured to trichlorfon for 12h and 24h, the proliferation of cortical neuron was inhibitted in different degrees. And the cell survival rates of exposured groups were lower than those of control groups.②Treated with trichlorfon for 12h, the ultrastrucyure of cells changed, which showed that the nuclei shrinkage, mitochondria blurred and mitochondria bloated.③Exposured to different concentrations of trichlorfon for 12h, the apoptosis rate increased significantly. Hoechst 33258 staining, the exposure groups showed that the nucleus crimpled and crescent liked, even nucleus fragmentation, which all belonged to typical characteristics of apoptosis.④Neuron's mitochondrial membrane potential descended with different concentrations of trichlorfon after culturing 12h. And the 80mg/L group decreased very significantly, compared with the control group (P<0.01).⑤Exposured to trichlorfon for 0.5h, [Ca2+]i in exposure groups increased very significantly compared with the control group (P< 0.01); Exposured with trichlorfon for 12h, [Ca2+]i in exposured groups decreased, but still indicated significanly or very significantly higher than the control group (P<0.05 or P<0.01).⑥Exposured to trichlorfon for 12h and 24h, intracellular ROS levels were significanly or very significantly higher than the control group (P<0.05 or P<0.01).⑦Exposured to trichlorfon for 12h, the activities of neuron's Na+-K+-ATPase and Ca2+-Mg2+-ATPase became low. And compared with the control group,20mg/L and 80mg/L groups indicated very significantly decreased (P<0.01).⑧The indicators showed significant changes in dose-effect relationship. The results showed that exposured to different concentrations of trichlorfon can lead to rat cortical neuron's viability decreased, morphology injuried, apoptosis rate and intracellular ROS levels increased, mitochondrial membrane potential decreased, the intracellular calcium overloaded and ATPase activity decreased. It prompted that the apoptosis played a leading role in the trichlorfon-induced rat cerebral cortical neurons'injury.