Expression of iNOS in the hippocampus in rats with vascular dementia

Objective To explore the expression of iNOS in the hippocampus in a rat model of vascular dementia.Methods The 60 rats were randomly divided into five groups:control group,12-hour model group,1-day model group,3-day model group,7-day model group, 12 rats in each group.Animal model of vascular dementia (VD) was established through repeated cerebral ischemia-reperfusion in rats.The number of neuron in CA 1 area of hippocampus in each group was observed with HE stain. Expression of iNOS in the hippocampus was measured with immunohistochemical staining and western blot methods. Results The number of neuron in CA 1 area of hippocampus decreased significantly in 12-hour group,1-day group,3-day group,and 7-day group.iNOS concentrations determined by western blot were up-regulated in 12-h group.The concentration increased further in 1-day group and maintained at this level to 7 day. Immunohistochemical staining showed that iNOS in CA 1 area of hippocampus had very weak expression in normal rats' group and increased gradually in 12-hour,1-day,3-day and 7-day group. Conclusions iNOS may be related to the injury of hippocampus neuronal cells in vascular dementia.It might be one of the reasons causing vascular dementia.