Abstract: ObjectiveTo explore neuron damage caused by iron overlosd in longterm lead(Pb) exposure rats.MethodsSprague-Dawley maternal and pup rats were randomly divided into control groups(without lead exposure),low exposure groups(with 800 and 300 mg/L lead acetate in drinking warter for maternal and pup rats),and high expoure groups(with 1500 and 900 mg/L lead acetate in drinking water for maternal and pup rats).The treatments lasted for 70 weeks.The contents of Pb and iron in blood and brain were determined with inductively coupled plasma atomic emission spectrometry (ICP-AES).Two adjacent hippocampus paraffin slices(3 μm apart from each other) were stained with ferric iron and thionine,then the images were merged.ResultsThe lead concentrations in blood and brain and Fe levels of hippocampus were significantly higher(P<0.01) after the exposure of lead.The intergrated optical density(IOD) for Perl's staining of CA3 of low and high lead exposure groups of were 5 930.71±2 517.6 and 11 382.43±2 551.14,and significantly higher than that of the control (3 786.78± 1 256.37) (P<0.01).The numbers of neurons in CA1 of low and high lead-exposure group were 70.71±11.80 cells/view and 70.37±17.53 and significantly lower than that of the control (83.71±12.60) (P<0.05).Image mergence by IPP6.0 indicated that the number and layer of the neurons were decreased and the injuries of the neurons were aggravated.ConclusionImage mergence of Perl's and thionine staining can intuitively be used for quantitative analysis of neuron damage caused by iron overload.