The Change Of SOD Activity, MDA And HSP70 In The Rat Brain After Penicillin-induced Seizures

Background Epilepsy is one of the commonly nervous systemic disease. Penicillin is commonly used to creating animal model of epilepsy. Many scholars induced successfully epileptic animal model by intraperitoneal injection of penicillin to investigate its pathogenesis and therapeutics. The maleic dialdehyde (MDA) is indirectly a marker of the metabolism of oxygen-derived free radidicals in vivo and the free radical damage degree. The superoxide dismutase (SOD) is an important substance to clean the oxygen-derived free radidicals. The heat shock protein 70 (HSP70) is the conservative stress protein after stimulation in the heat shock protein (HSP) family. It is reported that HSP70 protein expression increased in the cerebral tissue after epileptic seizures induced by kainic acid (KA) or pentylenetrazol. In this investigation, the objective is to investigate the expression of HSP70 and the level of SOD and MDA in the rat brain after penicillin-induced seizures. At the same time, we try to investigate the pathogenesis of epilepsy and give clinical physician some advice about epileptic therapy.Methods Systemic use of high-dose penicillin was studied in rats to establish an experimental model of epilepsy. Intraperitoneal injection of penicillin (8 million unit/kg body weight) was used to induce seizure. The activity of SOD and level of MDA were assayed by chemo-colorimetric method in the cerebral cortex and hippocampus. The levels of HSP70were detected by using immunohistochemical technique.Results Rats that injected penicillin were induced status epilepsy. Preventive matched control rat, the activity of SOD of epileptic rat brain were decreased significantly in the cerebral cortex and hippocampus after seizures (p < 0.01); Meanwhile, the content of MDA was notably increased (p<0.01); HSP70 expression increased significantly in the cerebral tissue after epileptic seizures, at the same time, the level of HSP70 in hippocampus was higher than that in cerebral cortex.Conclusion The results indicate that intraperitoneal injection of a certain number of penicillin was effective to induce seizure. This study suggests that the activities of SOD and the level of MDA can be used as clinical diagnosis indicators. Meanwhile, these data indicate that HSP70 expression increased in the cerebral tissue after epileptic seizures. The results suggested that the change of HSP70 in the cerebral tissue may protect the cell from injuring. In addition, our investigation also calls the medical doctors attention to the dosage of penicillin to reduce its toxicity for nervous system.