| Objective:Epilepsy is a chronic clinical syndrome characterized by a sudden, repeated and transient function of the central nervous system disorder caused by a excessive release of neurons. In recent years,people quest the pathogenesis of epilepsy from gene, molecular cytology and electrophysiology. The result is that potassium channels have relation with epilepsy. Potassium ion channels are widespread and type most,they are to exist all eukaryocyte, mainly participate in cell membrane resting potential and the regulation of action potential during Repolarization. They determine resting membrane potential and nerve excitability threshold, the control of membrane excitability and stability of the shape and frequency of action potentials.Potassium channelsKvl.4 and Kv4.1 are mainly located in nerve cells,potassium ions through the passage of channels are in the formation of a transient outward K+ current that is A-type potassium current (IA). This potassium channel below the threshold potential is activated when you start to produce export-oriented IA stimulus offset current, the depolarization was almost inhibited, extended membrane potential depolarization. Thus, Kvl.4 and Kv4.1were involved in repolarization potential adjustments affect the spike threshold, and re-issuing the primary mechanism for electricity. This study aim to detect the protein expression of Kv1.4 and Kv4.1 of rat hippocampus seizured before and after by immunohistochemistry technique and WesternBlot,discussing if Kvl.4 and Kv4.1 have relation with epilepsy,finally providing experience basis for diagnosis and treatment of epilepsy.Methods:Experimental animals were made acute generalized tonic-clonic seizure model by intraperitoneal injection 1% PTZ 40mg/kg,20mg/kg after ten minutes.Experimental animals were divided randomly normal group and epileptic group at 1h,24h,72h after seizures.Rats were killed at above time points and brain tissue was separated into two halves.One half was used immunohistochemical to detece the expression of potassium channel Kv1.4 and Kv4.1. Hippocampus from another half was used Western Blot to detect the expression of potassium channel Kv1.4 and Kv4.1.Results:1. The result of epilepsy model:27 of 30 rats of the experimental groups appeared generalized clonic, opisthotonos, orthocolosis, falling after the second injection of PTZ,reaching Racine standard 4～5. EEG was markedly abnormal, showing disseminated spike wave,sharp wave and spike and slow wave complex.another three rats were dead and rejected experimental groups.2. Results of the expression of Kv1.4 and Kv4.1 protein in hippocampus by Immunohistochemical staining:Kv1.4 protein were found to be abundantly expressed in rat hippocampus of normal group and experimental group.Normal group:positive reaction grain was found in cytoplasm, cell membrane and ax on. especially in CA1and CA3 region.Positive cell of experimental group was less than normal group. positive cell was fusiformis and staining light.AOD of Experimental groups had significant difference with control group (P <0.05). There was no significant difference between every time periods of experimental groups (P> 0.05).Kv4.1 protein were found to be abundantly expressed in rat hippocampus of normal group and experimental group.Control group:claybank positive reaction grain could be found in cytoplasm and cell membrane under high power lens and staining light.Positive cell of experimental group was more than normal group, which was fusiformis and expressed obviously in CA1 and CA3 regions.AOD of experimental groups had significant difference with control group (P<0.05).Each time point had no significant difference.3. Result of relative concentration of Kv1.4 and Kv4.1 protein by WB:Kv1.4 and Kv4.1 were found to be expressed in hippocampal neuron.Kv1.4 of experimental group was descend,while Kv4.1 was up-regulation. After seizures (at 1h,24h and 72h) the relative concentration of Kv1.4 and Kv4.1 protein had significant difference with control group(P<0.05);while each time point of experimental groups had no obvious difference(P>0.05) Conclusion:1. The expression of voltage -gate potassium channel Kv1.4 in Hippocampus brain tissues after injecting PTZ was obviously reduce2. The expression of voltage -gate potassium channel Kv4.1 in Hippocampus brain tissues after injecting PTZ was was increase... |
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