Toxic effect of low-level lead on primary cultured cerebral cortical neurons

To study the impact of low-level lead on the survival and apoptosis of primary cultured cortical neurons,develop a method of primary culture cortical neurons of newborn SD rats and establish experiment cell model of the neurons.Being treated with different dosage of lead acetate,the survival of the cultured cells were observed at different time-point by measurement of optical density(D) value in MTT method.The apoptosis of neurons was investigated by Hoechst 33258 fluorescent staining and flow cytometry.The results showed that low level of 50 μmol/L Pb2+ could promote the neurons′ growth in a short time(100.27%±1.61%),however,depressant effect was displayed after 6 h(99.20%±0.13%).Cell survival rate was gradually decreased when increased Pb2+ and prolonged time,in comparison with control group,significant decrease was observed after 12 h(P0.05).Cell nucleus developed crescentiform,chromatin condense,apoptotic body and nuclear fragmentation.Apoptotic rate was gradually increased with of increasing concentration Pb2+(0.7%,1.1%,1.5%,1.9%,2.2%).The data indicated that low-level lead could inhibit the neurons′ survival and promote neuron apoptosis.