ABSTRACT
Objective To observe the effects of interleukin-1β (IL-1β) and pentylenetetrazol (PTZ) induced acute epilepsy and the dynamic expression of aquaporin-4 (AQP4) in hippocampus. To explore the role of IL-1β in the pathogenesis of epilepsy by regulating AQP4. Methods All rats were randomly divided into control group, IL-1β group, PTZ group, IL-1ra + PTZ group and dexamethasone + PTZ group. Observe the behavior of the rats within 60 minutes after injection and record seizure score in each group. Then immunohistochemistry and RT-qPCR were used to detect the expression of AQP4 at at 6 , 12, 24 and 36 h. Results Almost of rats in IL-1β group and PTZ group showed severe degree seizure. The rats in control group and dexamethasone + PTZ group showed no obvious seizure. The seizure of rats were more remarkable serious in PTZ group than that in the IL-1ra + pentylenetetrazole group (P < 0.05). Immunohistochemistry and RT-qPCR Show: the expression of AQP4 in hippocampus in PTZ group increased gradually after 12 h (P < 0.05), then reached in the peak after 24 h (P < 0.001). The expression of AQP4 in IL-1ra + PTZ group was lower compare with PTZ group in each time (P < 0.05). Although the expression of AQP4 in dexamethasone + PTZ group higher than the control group, it was not significantly different (P < 0.05). Conclusion The proinflammatory cytokine IL-1β break the balance of water in brain and increasing the concentration of extracellular excitatory amino acids or ions by upregulate the expression of AQP4 in order to promote the excitatory of neurons.
ABSTRACT
Objective To investigate the dynamic expression of the drug resistance protein P-glycoprotein (P-gp) within 72 hours in the pentylenetetrazol (PTZ)-induced status epilepticus (SE) model, and to identify the optimal detection time to inhibit P-gp. Methods mRNA and protein expressions of P-gp in rats hippocampal tissue were detected by using immunohistochemistry , RT-qPCR and Western blot at different time points after modeling (0, 3, 6, 12, 24, 48, 72 h). Results The mean density of P-gp protein in the hippocampus of status epilepticus model was 0.325 1 ± 0.008 2 at 24 h, and was 0.396 3 ± 0.016 8 at 48 h, which were consistently higher than those of the control group (P < 0.05, P < 0.01, respectively). Results of qRT-PCR showed that MDR1a expression was significantly upregulated at 24 h and at 48 h (P < 0.05, P < 0.01, respectively). Western blot assay revealed that P-gp protein was also significantly increased at 48 h after seizures (P < 0.05). Conclusions The upregulation of P-gp after SE peaked at 48 h, which maybe the optimal detection time to detect drug resistant after SE.
ABSTRACT
BACKGROUND: Tetramethylpyrazine has the protective effect against the central nervous system injury. The structural changes in Nissl bodies were regarded as a marker of neuron injury.OBJECTIVE: To investigate the effect of tetramethylpyrazine on the structure and the quantity of Nissl bodies of cerebral neurons in rat with epilepsy.DESIGN: A comparative study.SETTING: It was conducted at the Physiological Department of Medical School of Xianning College.MATERIALS: From September 2004 to March 2005, it was completed at the Anatomy Department of Tongji Medical College, Huazhong University of Science and Technology. Forty healthy SD rats aging 3-4 months, weighing (250±50) g and regardless of their gender, were selected.METHODS: Rats underwent anesthesia and craniotomy. Then their cerebral cortex were exposed for placing BL-410 Experimental System of Biological Function (TME, China) to record the bilateral EEG of the brain and the seizure in rats with penicillin-induced epilepsy group and the 10 mg/kg tetramethylpyrazine group, 20 mg/kg tetramethylpyrazine group and 40 mg/kg tetramethylpyrazine group. In control groups, the brains of rats were taken out at 1 hour after craniotomy. In penicillin-induced epilepsy group, their brains were taken out at 1 hour after penicillin-induced epilepsy. In 10 mg/kg tetramethylpyrazine group, 20 mg/kg tetramethylpyrazine group and 40 mg/kg tetramethylpyrazine group, after stable penicillin-induced epilepsy, tetramethylpyrazine was injected intraperitoneally at a dose of 10 mg/kg, 20 mg/kg and 40 mg/kg, respectively.When the greatest protective effect of tetramethylpyrazine appeared, the rats' brains were taken out. Brain sections were sliced. Nissl bodies were stained by thionine staining. Under light microscope, structures of Nissl bodies were observed and the images of Nissl bodies were quantitatively analyzed by HPIAS-1000 high acuity color pathologic diagram-writing analyzing system. In each group, the average absorbency of 15 fields was regarded as the average absorbency of Nissl bodies in that group.MAIN OUTCOME MEASURES: In all the groups, the structure and the quantity of Nissl bodies of cortical neurons in rats were studied.of the structure of Nissl bodies in external granular layer cells and external pyramidal layer cells. In control group, multi-layer blue-stained and clumplike or granule-like Nissl bodies could be observed. In penicillin-induced epilepsy group, Nissl bodies were completely resolved and disappeared. In 10 mg/kg tetramethylpyrazine group, Nissl bodies were partly or completely resolved. In 20 mg/kg tetramethylpyrazine group, the quantity of Nissl bodies was significantly increased as compared with those in penicillin-induced epilepsy group and the 10 mg/kg tetramethylpyrazine group. In 40 mg/kg tetramethylpyrazine group, the quantity and the structure of of the average absorbency of stained Nissl bodies in external granular layer cells and external pyramidal layer cells in rat cortex among all the groups.In penicillin-induced epilepsy group, the average absorbency were dramatically lower than that in control group (0.033±0.002, 0.756±0.035, t=4.93,P ＜ 0.01). In 20 mg/kg tetramethylpyrazine group and 40 mg/kg tetramethylpyrazine group, the average absorbency were significantly higher than that in penicillin-induced epilepsy group (0.435±0.011, 0.658±0.029, t=2.98,5.32, P ＜ 0.01). In 40 mg/kg tetramethylpyrazine group, the average absorbency were similar to that in control group (t=1.75, P ＞ 0.05).CONCLUSION: Tetramethylpyrazine can significantly elevated the concentration of Nissl bodies of neurons in rats with epilepsy. Changes in the structure and quantity of Nissl bodies of cerebral neurons may be closely associated with seizure, and tetramethylpyrazine can restore the structure and the quantity of Nissl bodies of neurons, regulate their functions and hereby, inhibit seizures.
ABSTRACT
BACKGROUND: Ligustrazine inhibits discharge of cerebral hippocampal neuron, penetrates blood-brain barrier effectively after absorbed in the body and is distributed extensively in cerebral cortex, brain stem, striate body, hippocampus, cerebellum and midbrain.OBJECTIVE: To probe into the influence of ligustrazine and its different concentrations after abdominal injection on cerebral cortical neural cell structure in epileptic rats induced by penicillin.DESIGN: Randomized control experiment.SETTING: Physiological Department of Xianning Medical College.MATERIALS: The experiment was performed in Anatomy Department of Tongji Medical College of Huazhong University of Science and Technology from September 2004 to March 2005. Forty healthy SD rats of clean grade were employed, of either sex, mass weighted varied from 200 to 250 g.They were randomized into 5 groups, named operation control, penicillininduced epilepsy group and ligustrazine groups of 10 mg/kg, 20 mg/kg and 40 mg/kg, 8 rats in each group.METHODS: After anesthetized, the cranium was opened to expose cerebral cortical record region. BL-410 biofunctional experimental system was used to record brain electricity bilaterally and epileptic discharge of cerebral cortex in penicillin-induced epilepsy group and ligustrazine groups of 10 mg/kg,20 mg/kg and 40 mg/kg. In the control, 1 hour after anesthesia and craniotomy, cerebrum was collected. In penicillin-induced epilepsy group, 1 hour after induction, cerebrum was collected. In ligustrazine groups of 10 mg/kg,20 mg/kg and 40 mg/kg, after penicillin-induced epileptic discharge was stable, ligustrazine of 10 mg/kg, 20 mg/kg and 40 mg/kg was injected abdominally successively, and cerebrum was collected when the most remarkable inhibition was achieved. Brain tissue section was prepared separately, with HE staining, the observation was done under optic microscope.MAIN OUTCOME MEASURES: Structure changes in cerebral cortical neural cells in rats of each group.In the control, the morphological structure of cerebral cortical neural cell alternations on cerebral cortical neural cell structure, karyopykosis, plasmarrhexis and vacuolar structure, but there was no Nissel bodies in cytomarrhexis, vacuolar structure and decreased Nissel bodies in cytoplasm with the control, there were decreased vacuoles in neural cell, increased cytoplasm and few Nissel bodies in cytoplasm and cell structural morpholcontrol, karyon was big, round and light stained; clot-like Nissel bodies were visible and cell structural morphology was in tendency to be normal.CONCLUSION: In penicillin-induced epilepsy, morphological structure of cerebral cortical neural cell in rats is abnormal. Tetramethylpyrazine of various dosages may improve at different degrees morphological structure of cerebral cortical neural cell, especially significantly at high dosage, by which, its inhibition on epileptic discharge in rats is achieved.