目的:探究硫化氢的抗癫痫机制即调控环磷酸鸟苷/蛋白激酶G（cGMP/PKG）信号通路对三磷酸腺苷敏感性钾通道（KATP）亚基Kir6.2表达的影响。方法:将60只SD大鼠按随机数字表法分为6个组（每组10只）：（1）正常对照组；（2）癫痫组；（3）硫化氢供体干预组；（4）硫化氢供体加PKG抑制剂（KT5823）组；（5）硫化氢供体加KATP抑制剂（格列本脲）组；（6）硫化氢供体正常对照组。采用腹腔注射戊四氮致大鼠癫痫发作，记录潜伏期、首次发作级别、持续时间；记录癫痫发作时海马脑电图的变化；采用 蛋白质印迹法和实时荧光定量聚合酶链反应法检测海马组织中PKG、Kir6.2 mRNA和蛋白的表达水平，酶联免疫吸附测定法检测海马组织中cGMP、磷酸化PKG的浓度。结果:癫痫组出现Ⅳ~Ⅴ级发作，级别为4.500（4.000，4.875）级，潜伏期短［（10.37±8.21） min］， 持续时间长［（69.50±24.37） s］。与癫痫组相比，硫化氢供体干预组的发作级别降低（n P=0.004），潜伏期延长（n P<0.001）和持续时间缩短（n P<0.001）。硫化氢供体加PKG抑制剂组与硫化氢供体干预组相比，潜伏期缩短（n P<0.001），持续时间延长（n P<0.001）。硫化氢供体干预组癫痫波明显减少，波幅与癫痫组相比差异有统计学意义（n P<0.001）；硫化氢供体加PKG抑制剂组与硫化氢供体干预组相比癫痫波增加，波幅增大（n P<0.001）。组间比较结果提示，各组PKG mRNA和蛋白的表达水平存在差异（分别为n n=5， n H=26.714， n P<0.001和n n=5， n F=30.597， n P<0.001）；其中与正常对照组相比，癫痫组PKG mRNA（分别为1.000±0.001和0.782±0.064，n P=0.023）和蛋白（分别为0.550±0.037和0.145±0.020，n P=0.042）的表达水平显著下降。组间比较结果提示，各组Kir6.2 mRNA和蛋白的表达水平存在差异（分别为n n=5， n H=27.761， n P<0.001和n n=5， n F=60.659， n P<0.001）；其中与正常对照组相比，癫痫组Kir6.2 mRNA（分别为1.000±0.001和0.897±0.033，n P=0.004）和蛋白（分别为0.384±0.035和0.215±0.016，n P=0.024）的表达水平显著下降，cGMP（n P<0.001）、磷酸化PKG（n P<0.001）的浓度降低；与癫痫组相比，硫化氢供体干预组PKG mRNA（n P=0.047）、Kir6.2 mRNA（n P=0.011）、PKG 蛋白（n P<0.001）和Kir6.2蛋白（n P<0.001）的表达水平则上升，cGMP、磷酸化PKG的浓度升高（均n P<0.001）；尤其是与硫化氢干预组相比，硫化氢供体加PKG抑制剂组PKG mRNA（n P=0.015）、Kir6.2 mRNA（n P=0.013）、PKG 蛋白（n P=0.027）和Kir6.2蛋白（n P=0.017）的表达水平下降，cGMP（n P=0.005）、磷酸化PKG（n P<0.001）的浓度降低。n 结论:硫化氢可抑制大鼠癫痫发作，其机制之一可能与激活海马中cGMP/PKG信号通路上调KATP通道亚基Kir6.2的表达从而降低海马的兴奋性有关。“,”Objective:To explore the effect of hydrogen sulfide (Hn 2S) on modulating the subunit Kir6.2 of adenosine triphosphate sensitive potassium channels via the cyclic guanosine monophosphate-dependent protein kinase (cGMP/PKG) signaling pathway in epileptic rat models.n Methods:Sixty adult male SD rats were randomly divided into the following six groups (10 rats in each group) by random number table method: control, epileptic, Hn 2S donor, Hn 2S donor+epileptic, KT5823 (one inhibitor of the cyclic guanosine monophosphate-dependent protein kinase)+Hn 2S donor+epileptic, and glibenclamide (one inhibitor of the adenosine triphosphate sensitive potassium channels)+Hn 2S donor+epileptic groups. Except the control group, SD rats were intraperitoneally injected with plentylenetetrazole to make the kindling models and their behaviours were recorded including the latency period, the grade, and the duration of the first epileptic seizure according to the Racine′s standard. The waveforms of electroencephalogram (EEG) in hippocampus were also recorded during the seizure. The mRNA and protein levels of PKG and Kir6.2 in hippocampus were evaluated by Western blotting and quantitative real-time polymerase chain reaction, and the hippocampal concentrations of cGMP and phosphorylation of cyclic guanosine monophosphate-dependent protein kinase (p-PKG) were detected by enzyme linked immunosorbent assay.n Results:Rats in the epileptic group showed Ⅳ-Ⅴ grade of epileptic seizure [4.500 (4.000, 4.875)], short latency period [(10.37±8.21) min] but long duration [(69.50±24.37) s] of seizure. Compared to the epileptic group, rats in the Hn 2S donor group showed Ⅱ-Ⅲ grade of epileptic seizure (n P=0.004), significantly longer latency period (n P<0.001), and shorter duration of seizure (n P<0.001). Compared to the Hn 2S donor+epileptic group, rats in the KT5823+Hn 2S donor+epileptic group showed Ⅲ-Ⅳ grade of epileptic seizures, significantly shorter latency period (n P<0.001), and longer duration of seizure (n P<0.001). The results of EEG showed that the wave patterns in the epileptic group were spike or sharp waves and the amplitudes were largest [(190.570±23.590) μV]. Compared with the epileptic group, amplitudes were reduced (n P<0.001) in the Hn 2S donor+epileptic group. PKG mRNA and PKG protein were expressed differently among all groups (PKG mRNA: n n=5, n H=26.714, n P<0.001; PKG protein:n n=5, n F=30.597, n P<0.001). Compared with the control group, the expression of both PKG mRNA and PKG protein was decreased (PKG mRNA: 1.000±0.001n vs 0.782±0.064, n P=0.023; PKG protein: 0.550±0.037 n vs 0.145±0.020, n P=0.042) in the epileptic group. Besides, Kir6.2 mRNA and Kir6.2 protein were expressed differently among all groups (Kir6.2 mRNA: n n=5, n H=27.761, n P<0.001; Kir6.2 protein:n n=5, n F=60.659, n P<0.001). Compared with the control group, the expression of both Kir6.2 mRNA and Kir6.2 protein was decreased (Kir6.2 mRNA: 1.000±0.001n vs 0.897±0.033, n P=0.004; Kir6.2 protein: 0.384±0.035 n vs 0.215±0.016, n P=0.024) in the epileptic group. And the concentrations of cGMP and p-PKG were decreased (cGMP: n P<0.001; p-PKG:n P<0.001) in the epileptic group. The results in the Hn 2S donor+epileptic group were up-regulated (PKG mRNA: n P=0.047; PKG protein: n P<0.001; Kir6.2 mRNA:n P=0.011; Kir6.2 protein: n P<0.001; cGMP:n P<0.001; p-PKG:n P<0.001) compared with the epileptic group. However, the results in the KT5823+Hn 2S donor+epileptic group were down-regulated (PKG mRNA: n P=0.015; PKG protein: n P=0.027; Kir6.2 mRNA: n P=0.013; Kir6.2 protein: n P=0.017; cGMP: n P=0.005; p-PKG: n P<0.001) compared with the Hn 2S donor+epileptic group.n Conclusion:A possible mechanism is that Hn 2S prevents the epileptic seizure from modulating the subunit Kir6.2 of ATP sensitive potassium channels via the cGMP/PKG signaling pathway.n