中药复方抗痫灵对戊四氮致痫大鼠脑组织海马凋亡相关因子C-fos蛋白表达的影响

目的:观察中药复方抗痫灵对戊四氮致痫大鼠海马组织中C-fos蛋白表达水平的影响,探讨中药复方抗痫灵治疗癫痫的可能作用机制。方法:将90只Wistar大鼠随机分成空白对照组(10只),戊四氮(PTZ)腹腔注射(ip)法造模组(80只)。将戊四氮所诱导成功的癫痫大鼠随机分成5组,分别为癫痫模型组,丙戊酸钠治疗组,抗痫灵低剂量治疗组,抗痫灵中剂量治疗组,抗痫灵高剂量治疗组。观察大鼠痫性发作时,空白组、模型组及治疗各组大鼠行为,并采用免疫组化方法检测大鼠脑组织中海马C-fos蛋白表达,采用实时荧光定量(Real time PCR)方法检测大鼠海马组织中C-fos mRNA的相对表达。结果:各治疗组大鼠C-fos蛋白阳性目标面密度值较模型组均显著降低,差异具有统计学意义(P>0.01),但均未达到空白组水平(P<0.01);西药组和中药中剂量组的阳性目标面密度值与其他各组相比差异具有统计学意义(P>0.05);各治疗组之间相比差异无统计学意义(P>0.05),模型组大鼠海马中C-fos mRNA表达较模型组均显著降低,差异具有统计学意义(P<0.05),但均未达到空白组水平(P<0.01)。结论:中药复方抗痫灵对癫痫病的抗痫作用可能是通过降低癫痫大鼠大脑内C-fos的水平从而抑制神经元细胞的凋亡而达到抗癫痫作用的。

Activation of metabotropic glutamate receptor 1 regulates hippocampal CA1 region excitability in rats with status epilepticus by suppressing the HCN1 channel

Dysregulation of hyperpolarization-activated cyclic nucleotide-gated cation(HCN)channels alters neuronal excitability.However,the role of HCN channels in status epilepticus is not fully understood.In this study,we established rat models of pentylenetetrazole-induced status epilepticus.We performed western blot assays and immunofluorescence staining.Our results showed that HCN1 channel protein expression,particularly HCN1 surface protein,was significantly decreased in the hippocampal CA1 region,whereas the expression of HCN2 channel protein was unchanged.Moreover,metabolic glutamate receptor 1(mGluR1)protein expression was increased after status epilepticus.The mGluR1 agonist(RS)-3,5-dihydroxyphenylglycine injected intracerebroventricularly increased the sensitivity and severity of pentylenetetrazole-induced status epilepticus,whereas application of the mGluR1 antagonist(+)-2-methyl-4-carboxyphenylglycine(LY367385)alleviated the severity of pentylenetetrazole-induced status epilepticus.The results from double immunofluorescence labeling revealed that mGluR1 and HCN1 were co-localized in the CA1 region.Subsequently,a protein kinase A inhibitor(H89)administered intraperitoneally successfully reversed HCN1 channel inhibition,thereby suppressing the severity and prolonging the latency of pentylenetetrazole-induced status epilepticus.Furthermore,H89 reduced the level of mGluR1,downregulated cyclic adenosine monophosphate(cAMP)/protein kinase A expression,significantly increased tetratricopeptide repeat-containing Rab8b-interacting protein(TRIP8b)(1a-4)expression,and restored TRIP8b(1b-2)levels.TRIP8b(1a-4)and TRIP8b(1b-2)are subunits of Rab8b interacting protein that regulate HCN1 surface protein.

Chaihushugan decoction exerts antiepileptic effects by increasing hippocampal glutamate metabolism in pentylenetetrazole-kindled rats

OBJECTIVE: To investigate the antiepileptic effects of Chaihushugan decoction(CHSGD) in rats with pentylenetetrazole(PTZ)-induced seizures and to discuss the impact of CHSGD on glutamate metabolism, a hypothesized underlying mechanism of seizure reduction.METHODS: Fifty Wistar rats were divided randomly into either control(n = 10) or experimental(n = 40)groups. Rats in the control group were administered physiological saline intraperitoneally. A subconvulsive dose of PTZ(35 mg/kg) was administered intraperitoneally to rats in the experimental group to induce seizures. The fully PTZ-kindled rats were then randomly divided into five subgroups(n = 8 each) based on the following treatment categories: physiological saline, VPA(200 mg/kg), CHSGD(2.5 g/kg), CHSGD(5 g/kg), or CHSGD(10 g/kg),administered orally once per day, respectively. On day 28 following initiation of drug treatment, seizures were monitored. The rats were then sacrificed, and hippocampal dissections were performed for subsequent studies.RESULTS: CHSGD significantly prolonged the latency of myoclonic, clonic, and tonic seizures, while decreasing overall seizure rates in the kindled rats.The measured concentrations of 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-d-glucose(2-NBDG) and glutamate were significantly lower in the hippocampi of kindled rats in groups treated with CHSGD compared with those treated with PTZ alone. In addition, CHSGD was found to up-regulate both the expression of glutamate transporter-1(GLT-1) protein and the activity of glutamine synthetase(GS) in the hippocampi of kindled rats.CONCLUSION: These results suggest that CHSGD has antiepileptic effects on PTZ-induced seizures.The results further suggest an increase in glutamate metabolism at the synaptic cleft is a putative underlying mechanism of seizure reduction.