Assessment of recombinant human erythropoietin efficiency on experimental childhood status epilepticus induced by lithium-pilocarpin

Purpose: Status epilepticus is a neurological emergency. Status epilepticus triggers a mixture of apoptotic and necrotic cell death within the hippocampus. This neuronal loss may induce the development of epilepsy and result in cognitive impairments. Erythropoietin mediates a number of biological actions within the central nervous system and has been shown to be neuroprotective. There is a few studies on neuroprotective agents in status epilepticus rat models in childhood. In the present study, we were investigated the effects of recombinant human erythropoietin on hippocampus of rat after lithium-piocarpin induced status epilepticus.Materials and methods: Dam reared totally 21 Wistar male rats in postnatally 21. day were included in the study. Animals were classified into three groups: 1-Control group, 2-Lithium-pilocarpin induced status epilepticus, 3- Lithium-pilocarpin induced status epilepticus and erythropoietin treated group. Erythropoietin treated group received recombinant human erythropoietin 10U/g intraperitoneally 40 minutes after pilocarpine injection. Injections had continued for 5 days. Rats were sacrificed and brain tissues were collected at 5th day. Morphological changes in the hippocampi of rats were examined with respect to neuronal loss and neuronal apoptosis via TUNEL and caspase 3. One way ANOVA test was used for comparison of mean neuron numbers and immunuhistochemical scores.Results: Histopathological examination showed that, the number of neurons of CA1, CA2, CA3 and dentate gyrus regions in hippocampus were less in the status epilepticus group in comparison with the control group (p=0.001 for all comparisons). When compared with the status epilepticus group, the number of neurons of CA1, CA2, CA3 and dentate gyrus regions of hippocampus in the erythropoietin treated group statistically significantly increased (p=0.001 for all comparisons). The number of TUNEL positive cells in the CA1 and dentate gyrus regions of hippocampus of status epilepticus group were increased when compared with the control group (p=0.001 for all comparisons).We found that in the erythropoietin treated group the number of TUNEL positive cells in CA1 and dentate gyrus regions of hippocampus was significantly decreased when compared with status epilepticus group (p=0.001 for all comparisons). One sample was randomly chosen for each of the group for caspase-3 immune staining method. The ratios of caspase 3 in control group were 0.5% for CA1 and 0.75% for dentate gyrus, in status epilepticus group were 2.25% for CA1 and 2.% for dentate gyrus, in erythropoietin treated group 1.25% for CA1 and 1.75% for dentate gyrus. Although the number of caspase positive neurons of CA1 and dentate gyrus were less in the erythropoietin treated group when compared with the status epilepticus, it was not statistically evaluated.Conclusion:Erythropoietin significantly preserved the number of neurons and decreased apoptosis in the model of status epilepticus induced by lithium-pilocarpin. This experimental study indicates that erythropoietin administration can be neuroprotective in status epilepticus.Key words: Status epilepticus, rat, erythropoietin, neuroprotection