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[ ABSTRACT] AIM:To investigate the effect of edaravone ( ED) on the expression of caspase-3 and caspase-12 in the juvenile rat hippocampus after status convulsion ( SC) .METHODS: Juvenile male Sprague-Dawley rats were ran-domly divided into normal saline ( NS) control group, SC group and ED treatment group.The rats in each group were fur-ther divided into 5 subgroups according to different time points.The rats in SC group were kindled into epilepsy by lithium-pilocarpine chemical method.The protein expression of caspase-3 and caspase-12 was determined by immunohistochemistry methods.The mRNA expression of caspase-3 and caspase-12 was detected by RT-PCR.RESULTS:(1) The IA value of caspase-3 positive cells in 24~72 h SC group increased compared with NS group.With ED intervention, the IA value of caspase-3 positive cells decreased as compared with 48~72 h SC group.The results of RT-PCR showed that the mRNA ex-pression of caspase-3 was similar to the changes of protein.( 2 ) The results of immunohistochemistry showed that the IA value of caspase-12 positive cells in 12~72 h SC group increased compared with NS group.With ED intervention, the IA value of caspase-12 positive cells decreased as compared with 24~72 h SC group.The results of RT-PCR showed that the mRNA expression of caspase-12 was similar to the changes of protein.( 3 ) In ED group, Ⅴ grade convulsion was lower than that in SC group, and the latent period of seizures in ED group was significantly longer than that in SC group.CON-CLUSION:Edaravone inhibits the expression of caspase-3 and caspase-12 in pilocarpine-induced seizures in rat hippo-campus, suggesting that edaravone has protective effect against the damage caused by status convulsion.
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Objective To explore the role of glucose-regulated protein 78 (GRP78),p38 mitogen-activated protein kinase(p38MAPK) signal pathway in seizure-reduced brain injures and the regulatory effect of Nimodipine on it.Methods Sprague-Dawley(SD) rats were randomly divided into status convulsion group (SC group),Nimodipine group(NM group),and a normal control group(NC group).The expressions of GRP78/Bip and p38MAPK mRNA and protein were detected by reverse transcription(RT)-PCR and immunohistochemistry.The expression of apoptosis cells was observed by TdT-mediated dUTP nick end labeling (TUNEL).Results (1) Immunohistochemistry:at 4 h after induction of status convulsion,the expression of GRP78 protein in the hippocampus CA1 domain began increasing slightly,and reached a maximum at 24 h,and then began decreasing slowly ; at 4 h after induction of status convulsion,the expression of p38MAPK protein in the hippocampus CA1 domain began increasing,and reached a maximum at 24 h,and decreased remarkably at 48 h.(2) RT-PCR:at 4 h after induction of status convulsion,the expression of GRP78 protein in the hippocampus CA1 domain began increasing slightly,and reached a maximum at 24 h,and then began decreasing slowly.The NM group was much higher than the SC group and the NC group(all P ＜ 0.05) ; at 4 h after induction of status convulsion,the expression of p38MAPK protein in the hippocampus CA1 domain began increasing,and reached a maximum at 24 h,and decreased remarkably at 48 h;the NM group was much lower than the SC group,and higher than the NC group (all P ＜ 0.05).(3) TUNEL:at 4 h after induction of status convulsion,the expression of the TUNEL positive cells in the hippocampus CA1 domain began increasing slightly,and reached a maximum at 48 h,and then began decreasing,and there was no difference between SC group and NC group;the NM group was much lower than the SC group(all P ＜ 0.05).Conclusions The correlation of the increased expression of p38MAPK and neuronal apoptosis indicates that GRP78 signal pathway may be mediated to cell apoptosis through p38MAPK.Nimodipine can affect the expression of GRP78/Bip and p38MAPK,and relieve endoplasmic reticulum stress,and lessen the pathologic damage to the hippocampus.
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Objective To investigate the expression of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in hippocampus after status convulsion (SC) and explore the influence of age and duration of SC on the expression of BDNF and NGF. Methods Animal model with the different durations of SC (30 min,3h) were established by intraperitoneal injection of 3 mEq/kg lithium chloride,18-20 h later,followed by 5 mg/kg pilocarpine in 40 adult Wistar rats aged 2-3 months and 40 20-day-old Wistar rats. The normal control and experimental control were made in ten adult rats and ten 20-day-old rats (n=5 for each control). The rats were sacrificed at 3 h,6 h,12 h,1 d,3 d,7 d after 30-minute SC,or 3 h,1 d after 3-hour SC respectively. The location and cell type expression of BDNF and NGF in the hippocampus were observed by immunohistochemistry. The levels of BDNF and NGF at different time points were quantitatively analyzed by enzyme-linked immunosorbent assay (ELISA). Results The cells expressing BDNF and NGF located mainly in the dentate granule cells and CA1-CA4 pyramidal cells of hippocampus. The most positive immunoreactivity was in cytoplasm,partly in axons. The expression of BDNF had the tendency of increase in all rats after 3-hour SC,peaked at 1 d and 3 d respectively. These increases lasted for at least 7 d. Moreover,a several-fold increase was observed at the peak levels. The patterns of NGF expression were similar to that of BDNF after SC. The elevated degree and duration of NGF expression were remarkably lower than that of BDNF,declining abruptly to below control levels by 12 h with the characteristic of biphasic increase. The expression of hippocampal BDNF had the positive correlation with the duration of SC,but that of NGF was not. No matter the duration of SC,there was more rapid and evident induction of BDNF in 20-day-old rats and adult rats. Moreover,the age-related difference was more obvious for the longer duration of SC. Conclusion SC induced the expression of BDNF chiefly in hippocampus,and had minor influence on that of NGF. The expression of BDNF was related to age and duration of SC. There was a more rapid and marked induction of BDNF in 20-day-old rats and adult rats. The age-related difference had the positive correlation with the duration of SC.