Objective To explore the temporal and spatial distribution of CCAAT/enhancer-binding protein homologous protein (CHOP) and calnexin (CNX) in the dentate gyrus of mesial temporal lobe epilepsy (mTLE) mouse model. Methods We used kainic acid (KA) to induce acute phase (12 h and 24 h) mTLE mouse models and performed Western blotting and immunofluorescence to detect the different expressions and distribution pattern of CHOP and CNX in CA3 of the hippocampus. Results Compared with the controls,the expressions of CHOP(F=1.136,P=0.4069) and CNX (F=2.378,P=0.2087) did not increase in CA3 of hippocampus 12 h following KA injection in the acute phase of mTLE mouse models,whereas the expressions in CA1 and CA3 of hippocampus 24 h after injection were significantly higher (F=8.510,P=0.0362;F=6.968,P=0.0497,respectively). As shown by immunofluorescence analysis,CHOP was expressed mainly in CA3 of hippocampus 12 h after KA injection,and increased in CA1 and CA3 24 h after KA administration. Compared with the controls,the expressions of CHOP(F=24.480,P=0.0057) and CNX (F=7.149,P=0.0478) were significantly higher 24 h after KA injection.Conclusions The expression of CHOP increases along with the progression of seizures,indicating the increased level of endoplasmic reticulum stress. An increasing number of CNX,which serves as molecular chaperone,may be needed to facilitate the unfolded protein to complete the folding process.
Animals ; Calnexin ; metabolism ; Dentate Gyrus ; metabolism ; Disease Models, Animal ; Epilepsy, Temporal Lobe ; chemically induced ; metabolism ; Kainic Acid ; Mice ; Seizures ; chemically induced ; metabolism ; Transcription Factor CHOP ; metabolism

OBJECTIVEFlavonoids are present in foods such as fruits and vegetables. Several studies have demonstrated a relationship between the consumption of flavonoid-rich foods and prevention of human disease, including neurodegenerative disorders. We assessed the effect of rutin (quercetin-3-O-rutinoside) on oxidative stress in kainic acid (KA)-induced seizure.

METHODSThirty-six BALB/c mice were randomly divided into three groups. In the control group, saline (intra-peritoneal, i.p.) was administered for 7 d, and on the last day, KA (10 mg/kg, i.p.) was injected 30 min after administration of saline. In rutin groups, mice were pretreated with rutin (100 and 200 mg/kg, i.p.) for 7 d, and on the last day, KA (10 mg/kg, i.p.) was injected 30 min after administration of rutin. Subsequently, behavioural changes were observed in mice. Lipid peroxidation and oxidative stress were measured respectively in the early and late phases after KA-induced seizures.

RESULTSSeizure scores in the rutin groups were significantly lower than those in the control group (P < 0.01). Furthermore, rutin dose-dependently inhibited the number of wet-dog shakes (WDS) (P < 0.05). Malondialdehyde level in the hippocampus of the rutin groups was significantly lower than that in the hippocampus of the control group on days 1 and 21 after KA administration. In the rutin groups, the thiol levels observed on day 1 after KA administration were higher than that in the control group (P < 0.01).

CONCLUSIONThese results indicate that rutin has potential anticonvulsant and antioxidative activities against oxidative stress in KA-induced seizure in mice.

Animals ; Dose-Response Relationship, Drug ; Kainic Acid ; toxicity ; Lipid Peroxidation ; drug effects ; Male ; Mice ; Mice, Inbred BALB C ; Oxidative Stress ; drug effects ; Rutin ; pharmacology ; Seizures ; chemically induced ; metabolism ; Sulfhydryl Compounds ; analysis

BACKGROUNDCurcumin, an active ingredient of turmeric with antioxidant and anti-inflammatory properties has recently been reported to have anticonvulsant effects in several animal models of epilepsy. This study aimed to investigate the effects of curcumin on the pilocarpine rat model of status epilepticus.

METHODSThe effect of intraperitoneal administration of curcumin (30, 100, and 300 mg/kg) on pilocarpine-induced seizures in rats was tested. The correlation between seizure activity and hippocampal levels of nitric oxide synthase and free radicals was quantified. Whether curcumin treatment modulated these parameters was also investigated.

RESULTSCurcumin significantly increased seizure threshold at doses of 100 and 300 mg/kg. Rats with pilocarpine- induced seizures showed significantly elevated levels of malonaldehyde, nitric oxide synthase, and lactate dehydrogenase, but decreased levels of superoxide dismutase and glutathione compared with normal control rats. At doses of 100 and 300 mg/kg, curcumin reversed the effects of pilocarpine-induced seizures on nitric oxide synthase, lactate dehydrogenase, glutathione, and superoxide dismutase. However, curcumin did not restore the elevated malonaldehyde levels.

CONCLUSIONCurcumin has anticonvulsant activity in the pilocarpine rat model of seizures, and that modulation of free radicals and nitric oxide synthase may be involved in this effect.

Animals ; Anticonvulsants ; therapeutic use ; Antioxidants ; therapeutic use ; Curcumin ; therapeutic use ; Glutathione ; metabolism ; Lipid Peroxidation ; drug effects ; Male ; Malondialdehyde ; metabolism ; Oxidative Stress ; drug effects ; Pilocarpine ; toxicity ; Rats ; Rats, Sprague-Dawley ; Seizures ; chemically induced ; drug therapy ; metabolism ; Superoxide Dismutase ; metabolism

OBJECTIVEIn the past the mortality and sequelae rate of the patients with severe fluoroacetamide (FAM) poisoning treated only with traditional remedies was high. During the recent ten years the authors treated children with severe FAM poisoning with charcoal hemoperfusion (HP) and achieved better results. However evidence was not sufficient to show that reduced mortality and sequelae rates were obtained from HP without traditional treatment because of lack of prospective randomized, controlled clinical studies. Thus, a dog model for FAM poisoning was designed in order to study the therapeutic effect, high-efficiency time of HP, the time of tissue-poisoning to release after HP, and to investigate the toxicokinetics of the poison in the course of treatment and after HP.

METHODFourteen dogs were given intraperitoneal FAM at a dose of 0.3 mg/kg body weight. HP was performed on 9 poisoned dogs for 30 - 120 minutes post intoxication. Each procedure lasted for 4 hours. Blood samples of the 9 poisoned dogs were collected before HP and 30, 60, 90, 120, 180, 240 minutes during HP and 2, 6, 24 hours after HP. Blood plasma was separated from blood samples and stored at -20 degrees C. The concentration of the poison was measured by gas chromatography (GC). The clinical symptoms of all the dogs were observed for one day.

RESULTSThe FAM concentration (ng/ml) of blood samples in poisoned dogs before HP, and 60, 120, 180, 240 minutes during HP were 230.11 +/- 52.48, 184.56 +/- 62.57, 141.00 +/- 44.83, 126.78 +/- 61.04, 113.11 +/- 54.65 respectively. The differences were significant (chi(2) = 31.978, P < 0.0005). The dispersion count between pre-HP and HP for 1 was 45.55, between 1 h and 2 h was 43.56, between 2 h and 3 h was 14.22 and between 3 h and 4 h was 13.67. The values of FAM had declined by 38.7%, 45.0% and 50.8% respectively at 2 h, 3 h, 4 h of HP compared with pre-HP. The rate of cleaning efficacy of FAM of every hour during HP were 19.79%, 23.6%, 10.09% and 10.78% respectively during HP 1, 2, 3, 4 h. The cleaning efficacy of HP was high within 2 hours during HP. The concentration of FAM slightly rose again 6 h after HP. The level of FAM had declined at 24 hour after HP when compared with pre-HP level. The reduction rate of FAM level for every hour during HP was higher than that after HP (12.71% vs 0.27% - 2.22%). The t(1/2) of FAM with and without HP were (4.50 +/- 1.20) h and (49.60 +/- 10.56) h. All the 5 poisoned dogs not treated with HP died. However 6 poisoned dogs treated with HP kept alive after HP. Three dogs had frequent seizures again 4h after HP. After HP the charcoal container was washed by 0.9% saline and FAM could not be detected in the douche.

CONCLUSIONSCharcoal HP was an effective treatment for severe FAM poisoning. T(1/2) of the poison was shortened, and the poison clearing rate was accelerated by HP. The high-efficiency time of HP was 2 - 2.5 h. Activated charcoal can adsorb the poison vigorously, and return of blood to the body after HP by using 0.9% saline was feasible and safe.

Animals ; Charcoal ; therapeutic use ; Dogs ; Fluoroacetates ; poisoning ; Hemoperfusion ; methods ; Metabolic Clearance Rate ; Poisoning ; metabolism ; therapy ; Poisons ; toxicity ; Seizures ; chemically induced ; Treatment Outcome

OBJECTIVETo investigate the modulatory effects of morphine on the susceptibility to pentylenetetrazole-induced seizures, and the involvement of endogenous histamine in this process.

METHODSBoth the wild-type (WT) mice and histidine decarboxylase (a key enzyme for histamine biosynthesis) deficient (HDC-KO) mice were subcutaneously injected with different doses of morphine, and 1 hour later the pentylenetetrazole solution (1.5 %) was infused into the tail vein at a constant rate of 0.3 ml/min. The minimal dose of pentylenetetrazole (mg/kg) needed to induce myoclonic jerks and clonus convulsion was recorded as the thresholds of seizures.

RESULTIn WT mice, morphine dose-dependently decreased the thresholds of both myoclonic jerks and clonus convulsion. In HDC-KO mice, morphine at 10 mg/kg only significantly decreased the threshold of myoclonic jerks from (38.6 +/-2.9)mg/kg to (32.5 +/-0.7)mg/kg, but had no significant effect on the threshold of clonus convulsion [from (51.8 +/-2.1)mg/kg to (47.6 +/-1.2)mg/kg]. In addition, the value of decreased myoclonic jerks (15.8 +/-1.4)% and clonus convulsion (8.3 +/-0.9)% thresholds were much lower in HDC-KO mice than in WT mice [(26.1 +/-2.5)% and (20.8 +/-2.4)%, respectively].

CONCLUSIONMorphine can decrease the thresholds of pentylenetetrazole in induction of seizure, and the endogenous histamine may be involved in this process.

Animals ; Disease Susceptibility ; chemically induced ; metabolism ; physiopathology ; Dose-Response Relationship, Drug ; Histamine ; metabolism ; physiology ; Histidine Decarboxylase ; genetics ; metabolism ; Male ; Mice ; Mice, Knockout ; Morphine ; pharmacology ; Myoclonus ; chemically induced ; metabolism ; physiopathology ; Narcotics ; pharmacology ; Pentylenetetrazole ; Random Allocation ; Seizures ; chemically induced ; genetics ; physiopathology ; Sensory Thresholds ; drug effects

Myristoylated alanine-rich C kinase substrate (MARCKS) is a widely distributed protein kinase C (PKC) substrate and has been implicated in actin cytoskeletal rearrangement in response to extracellular stimuli. Although MARCKS was extensively examined in various cell culture systems, the physiological function of MARCKS in the central nervous system has not been clearly understood. We investigated alterations of cellular distribution and phosphorylation of MARCKS in the hippocampus following kainic acid (KA)-induced seizures. KA (25 mg/kg, i.p.) was administered to eight to nine week-old C57BL/6 mice. Behavioral seizure activity was observed for 2 h after the onset of seizures and was terminated with diazepam (8 mg/kg, i.p.). The animals were sacrificed and analyzed at various points in time after the initiation of seizure activity. Using double-labeling immunofluorescence analysis, we demonstrated that the expression and phosphorylation of MARCKS was dramatically upregulated specifically in microglial cells after KA-induced seizures, but not in other types of glial cells. PKC alpha, beta I, beta II and delta, from various PKC isoforms examined, also were markedly upregulated, specifically in microglial cells. Moreover, immunoreactivities of phosphorylated MARCKS were co-localized in the activated microglia with those of the above isoforms of PKC. Taken together, our in vivo data suggest that MARCKS is closely linked to microglial activation processes, which are important in pathological conditions, such as neuroinflammation and neurodegeneration.
Up-Regulation/drug effects ; Time Factors ; Seizures/chemically induced/*metabolism ; Protein Kinase C-delta/analysis ; Protein Kinase C-alpha/analysis ; Protein Kinase C/*analysis ; Protein Biosynthesis/drug effects ; Phosphorylation/drug effects ; Microscopy, Confocal ; Microglia/cytology/drug effects/*metabolism ; Mice, Inbred C57BL ; Mice ; Membrane Proteins/*analysis/metabolism ; Kainic Acid/*toxicity ; Isoenzymes/analysis ; Intracellular Signaling Peptides and Proteins/*analysis/metabolism ; Immunohistochemistry ; Animals

OBJECTIVETo observe the histopathological changes in rat hippocampus at different maturational stages after repeated kindled seizures, and to explore their underlying epileptogenesis processes.

METHODSThree groups of Wistar rats (postnatal days: P10, P20, P60) were given pentylenetetrazol (PTZ) intraperitoneal injection for 5 days to induce repeated kindled seizures, and the age-matched rats in control group were injected with normal saline. The behavioral changes, the morphology and the neurons counting in hippocampus, as well as the expression of NF-kappaB were observed.

RESULTS(1) In the three groups, the latency of seizure and the latency of IV/V grade were significantly lower in the rats of group P10 and P20 [(1.2 +/- 0.6) min and (14.4 +/- 2.3) min vs. (4.7 +/- 1.6) min and (24.5 +/- 4.5) min] than group P60 [(8.6 +/- 2.0) min and (41.9 +/- 4.5) min], whereas the duration of convulsion in group P10 and P20 [(46.2 +/- 4.8) min and (29.8 +/- 5.9) min] was longer than those of group P60 [(17.1 +/- 5.0) min]. (2) The neuron counting of CA(1), CA(3) and hilar in the P10 and P20 groups showed no differences as compared to their controls, whereas adult rats (P60) had a significant neuron loss in CA(1) and CA(3) pyramidal cells, compared with the control group [(6.3 +/- 1.5)/250 microm(2), (3.6 +/- 1.4)/250 microm(2) vs. (8.2 +/- 1.9)/250 microm(2), (5.6 +/- 1.7)/250 microm(2)]. However, the dentate granule cells in immature rats (P10) with daily seizures had a significant increase as compared with the controls [(23.3 +/- 3.1)/250 microm(2) vs. (16.3 +/- 1.6)/250 microm(2)]. (3) Prominent sprouting was seen in the CA(3) stratum pyramidal layer in all experimental rats with 5 daily seizures, regardless of the age. But the degree of sprouting had significant differences among the experimental groups (P < 0.05). (4) NF-kappaB was expressed significantly in CA(3), CA(1) and dentate granule cells 24 hours after PTZ-kindling when compared with the control groups, with the spectral density decreased with age.

CONCLUSION(1) There were great differences in the vulnerability to the repeated seizure-induced brain damage at different maturational stages in rats. The immature brain appeared to be less vulnerable to the repeated seizures. (2) There was less hippocampus neuron loss and milder mossy fiber sprouting after repeated seizures in the developing rats than mature ones, which may be a pathological evidence underlying the prospect that the immature brain was more resistant to the seizure-induced neuronal injury. (3) The high expression of NF-kappaB may exert a certain biological effects in the seizure-induced neuronal injury.

Age Factors ; Animals ; Hippocampus ; drug effects ; pathology ; NF-kappa B ; metabolism ; Pentylenetetrazole ; adverse effects ; Rats ; Rats, Wistar ; Seizures ; chemically induced

OBJECTIVETo study the effects of immunoglobulin on the neuronal expression of IL-1beta and IL-1ra and the neuronal death at hippocampus in rats with convulsion induced by pentylenetetrazol.

METHODSThe epilepsy model was established by injecting intraperitoneally pentylenetetrazol (PTZ) into Wistar rats. Forty-five rats were randomly divided into three groups, normal control group, PTZ plus intravenous immunoglobulin (PTZ-IVIG); PTZ plus normal saline (PTZ-NS). Neuronal death was assessed by light microscopy with the hematoxylin-eosin (HE) staining and with in situ terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL). IL-1beta and IL-1ra expressions were examined by histochemistry.

RESULTSThe ratio of IL-1beta/IL-1ra at hippocampal CA(1) region in PTZ-IVIG group (0.5 +/- 0.1) was significantly lower than that in PTZ-NS group (1.9 +/- 0.5, t = 12.9, P < 0.05). Apoptotic cell numbers at the hippocampal CA(1) region were significantly decreased in the PTZ-IVIG group, compared to PTZ-NS group (t = 27.1, P < 0.05). The numbers of positive cells were 16.4 +/- 3.3/1000 microm(2) in the former and 41.7 +/- 3.5/1000 microm(2) in the latter. Necrotic cell numbers at the hippocampal CA(1) region were significantly decreased in the PTZ-IVIG group (19.0 +/- 2.6/1000 microm(2)), compared to PTZ-NS group (42.3 +/- 4.9/1000 microm(2), t = 20.9, P < 0.05).

CONCLUSIONImmunoglobulin could inhibit neuronal death induced by convulsion and its possible mechanism might be the regulation of IL-1 system in neurons.

Animals ; Apoptosis ; Hippocampus ; drug effects ; immunology ; metabolism ; Immunoglobulins, Intravenous ; pharmacology ; Interleukin 1 Receptor Antagonist Protein ; metabolism ; Interleukin-1beta ; metabolism ; Neurons ; drug effects ; Pentylenetetrazole ; adverse effects ; Rats ; Rats, Wistar ; Seizures ; chemically induced ; immunology ; metabolism

OBJECTIVERefractory temporal lobe epilepsy (TCE) shows a unique type of hippocampal damage, referred to as hippocampal sclerosis. The mechanisms underlying drug-refractoriness in TCE are poorly understood, which may be connected with pharmacoresistance to antiepileptic drugs (AEDs). Some studies show that expression of the multidrug resistance gene (mdr1a and mdr1b) and p-glycoprotein encoded by mdr1a and mdr1b are high in the brain, especially in the hippocampus, and the expression may lead to reduction of AEDs concentration in the brain. But most of these studies focused on acute epileptic activity shortly after status epilepticus (SE), spontaneous seizures are seldom studied. The authors used a rat model of kainic acid induced spontaneous seizures to investigate expression of mdr1a and mdr1b mRNA, and explore whether topiramate (TPM) affects expression of mdr1a and mdr1b in the hippocampus.

METHODSSeizures were induced by intraperitoneal injection of 10 mg/kg kainic acid at postnatal day 28. Control rats were injected with sodium chloride. All rats were divided into 4 groups 1 week after spontaneous seizures developed: status epilepticus complicated with spontaneous seizures (SE, n = 8) group, status epilepticus complicated with spontaneous seizures treated with TPM (SE + TPM, n = 9) group, spontaneous seizures without status epilepticus (N-SE, n = 7) group, spontaneous seizures without status epilepticus treated with TPM (N-SE + TPM, n = 8) group, control (n = 7) group and control treated with TPM (control + TPM, n = 7) group. The treated rats were given therapeutic dose of TPM (25 mg/kg). All the rats were killed on the 42nd day of administration. The mdr1a and mdr1b mRNAs in the hippocampus were measured by RT-PCR.

RESULTSExpression of mdr1a and mdr1b mRNA in the hippocampus increased significantly in the SE + TPM group, SE group and N-SE + TPM group compared with control group (P < 0.001 or < 0.05). The mRNA in SE + TPM group increased significantly compared with the SE group, too (P < 0.01). The mdr1a and mdr1b mRNA expression in the hippocampus in control + TPM and N-SE groups did not change.

CONCLUSIONFrequent seizures, especially status epilepticus resulted in overexpression of mdr1a and mdr1b mRNAs in the hippocampus. The drug-refractoriness mechanism in TCE may be related to overexpression of mdr1a and mdr1b mRNAs. TPM could enhance the expression of mdr1a and mdr1b mRNAs in the hippocampus. Seizure activity and TPM are likely to be the main determinant in enhancing mdr1a and mdr1b mRNA expression in epilepsy.

ATP-Binding Cassette, Sub-Family B, Member 1 ; metabolism ; Animals ; Anticonvulsants ; pharmacology ; Fructose ; analogs & derivatives ; pharmacology ; Hippocampus ; metabolism ; Kainic Acid ; RNA, Messenger ; metabolism ; Rats ; Seizures ; chemically induced ; drug therapy ; metabolism ; Status Epilepticus ; drug therapy ; metabolism

OBJECTIVETo investigate the expression of N-methyl-D-asparate (NMDA) receptor subunit proteins after administration of different doses of pentylenetetrazol (PTZ).

METHODSAfter ip injection of a subconvulsant (35 mg/kg) and convulsant (50 mg/kg) dose of PTZ, the rats were decapitated at different time points. The levels of cortical NR1 NR2A and NR2B subunit proteins were detected by immunoblotting.

RESULT35 mg/kg PTZ and 50 mg/kg PTZ elicited different behavioral changes (P<0.001). The NR2A subunit in the cortex significantly increased 1 h after PTZ injection (P<0.05). For the 50 mg/kg group, both the NR2A and NR2B subunits proteins increased at 1 h in the cortex and then decreased; the protein levels returned to normal after 48 h. However, NR1 subunit had no changes.

CONCLUSIONThe NR2 subunit is involved in PTZ-induced seizure.

Animals ; Cerebral Cortex ; chemistry ; Dose-Response Relationship, Drug ; Male ; Pentylenetetrazole ; administration & dosage ; Rats ; Rats, Sprague-Dawley ; Receptors, N-Methyl-D-Aspartate ; analysis ; Seizures ; chemically induced ; metabolism