[Abstract] Objective : To prepare a Wistar rat epilepsy model with lithium chloride-pilocarpine, and to explore the appropriate dosage and usage of pilocarpine. Methods : Wistar rats were intraperitoneally injected with lithium chloride 3mmol / kg. After 24h, different doses of pilocarpine were given intraperitoneally. RESULTS : The incidence and mortality of persistent epileptic seizures (SE) in the 40 mg/kg group and the 30 mg/kg one-injection group were 100%, and the success rate of the chronic recurrent epilepsy (SRS) model was 0%; 30 mg/kg The incidence rate of SE in the 3 injection groups was 28%, the mortality rate was 10%, and the SRS success rate was 18%. The SE rate of the 25 mg / kg 3 injection group was 10%, the mortality rate was 0%, and the SRS success rate was 10%. %. Conclusion : The Wistar rat epilepsy model was prepared with lithium chloride-pilocarpine. The dosage of lukapin should be 25-30 mg/kg. The fractional injection method is better than the single injection method. Epilepsy is a common disease. Because its seizures are not predictive, the degree of seizures cannot be artificially controlled, which brings difficulties to the study. Therefore, an experimental animal epilepsy model is established. For exploring the mechanism of epilepsy, screening and evaluating antiepileptic drugs The role is of great significance. There are many methods for the preparation of animal epilepsy models. The literature reports the status of epilepticus (SE) in rats induced by lithium chloride-pilocarpine injection for 1 h and survivors, ie, spontaneous seizures (SRS). Model [1, 2 ]  This epilepsy model is similar to the most common type of epilepsy in adults, namely temporal lobe epilepsy, and has the advantages of simple operation, good reproducibility, and low external interference. In this experiment, Wistar rat epilepsy model was prepared with lithium chloride-pilocarpine to investigate the specific dose and usage of pilocarpine. 1 Materials and methods 1. 1 Laboratory animals and grouping  Healthy female Wistar rats, weighing 210-260 g, were purchased from the Experimental Animal Breeding Center of the Chinese Academy of Medical Sciences to provide adequate food and water at room temperature and natural light. According to the injection dose of pilocarpine, it was divided into 40mg / kg injection group (6), 40mg/kg divided into 3 injection groups (4), 30mg/kg once injection group (5), 30mg/kg divided into 3 times. Injection group (50), 25 mg/kg divided into 3 injection groups (10). 1. 2 Preparation of epilepsy model  All the rats were intraperitoneally injected with lithium chloride 3mmol / kg at a concentration of 1. 5mol / L at 24h before the experiment.  [3] . After 24 h, different doses of pilocarpine were administered intraperitoneally (concentration 0.1%). The injection injection group is separated by 10 minutes each time.  [4] . In the case of persistent seizures (SE) and continued for 1 hour, a dose of 10 mg/kg diazepam was given to terminate [2] . 2 results 2. 1 Different performance statistics of each dose group  All rats developed symptoms of cholinergic peripheral nerve stimulation 5-10 min after the first injection of pilocarpine, ie, piloerection, salivation, and bloodletting, and showed varying degrees of performance, including: less movement, staring , mouth automatic disease, nodding, blinking, wet dog-like shaking; 33 rats with transient epileptic seizures: manifested as erect, forelimb and head palsy, falls, transient epileptic seizures begin at the first time After 30 minutes of injection, each time lasted for 30 to 45 s, then every 2 to 5 minutes. 30 rats developed persistent epileptic seizures (1 h), which was the same as transient epileptic seizures; 20 rats were persistent. 1 to 2 days after the epileptic seizures died; 10 SE survivors, spontaneous seizures occurred in 20 to 60 days, manifested as ear shaking, chewing, staring, etc., each lasting seconds to tens of seconds See Table 1. 2. 2 Comparison of successful groups of epilepsy models  See Table 2 ![]() Statistical analysis of SRS success rate in 25 mg/kg 3 injection groups and 30 mg / kg 3 injection groups (statistical method χ 2 test, χ 2 = 0. 38) : P > 0.05, ie there is no statistical difference between the above two methods . The above results show that the preparation of Wistar rat epilepsy model with lithium chloride-pilocarpine, the total amount of pilocarpine should be 25 ~ 30mg / kg, the dose of 40mg / kg can occur SE, but the mortality rate is very high When the total amount is 30mg / kg, the mortality rate is higher in one injection, and it should be injected in several stages. It can be increased or decreased according to the different performance of the rats to adapt to different individual differences. 3 Discussion The Wistar rat epilepsy model prepared by intraperitoneal injection with lithium chloride-pilocarpine has the 5-level behavior of Racine [5]  , namely: I mouth and face twitching; II head clonic movement; III forelimb clonic; IV clonic erect; V posture control loss (fall). Among them, grades I to III represent complex partial seizures, and grades IV to V represent secondary systemic seizures. This model is a good simulation of the whole process of human epilepsy, expansion and formation. It is the only animal model that is consistent with the most common clinical epilepsy in adults, namely the characteristics of temporal lobe epilepsy [6].  : It has the advantages of easy operation and good repeatability. It is an ideal model for the study of the occurrence and mechanism of epilepsy. The Wistar rat epilepsy model was prepared with lithium chloride-pilocarpine. It was reported that a single injection of 30 mg/kg of pilocarpine could cause SE to occur in 70% of rats, but although SE was terminated with stability for 90 min, there was still 45% of deaths; pilocarpine 30mg/kg divided injections, the mortality rate after SE decreased to less than 10%, and the probability of SRS after repeated low-dose repeated injections was greater than the probability of single-shot injections [7]  Therefore, the method of small-dose fractional injection is superior to the single-shot injection of large dose. The results of this experiment are consistent with the literature reports. Compared with the literature reports, the epilepsy model of this experiment has a low success rate and high mortality. The possible reasons are as follows: the experiment is female rats, and the literature is mostly male mice [1, 2, 6]  Different sex mice have different susceptibility to pilocarpine; it is reported that cholinergic neurons play a role in rats 2 weeks after birth, and acetyltransferase reaches 83% of rats in 4 weeks, therefore, rats Sensitivity to epilepsy in pilocarpine is age-dependent [8]  The mortality rate was the highest at 3 weeks, and the mortality rate in adult rats was decreased. The experiment was performed in adult rats, but it was slightly smaller than the reported ones. The above mice weighed 210-260 g. 250 ~ 300g), may be one of the reasons; atropine can antagonize the effects of pilocarpine on the epilepsy and damage to brain tissue, this experiment is not given atropine, but also one of the reasons. references: [1] Cavalheiro EA, Leite JP, Bortolot to ZA, et al. Long —term effects of pilocarpine in rats structural damage of the brain triggers kindling and spontaneous recurrent seizures [J ] .Epilepsia , 1991 , 32 : 778 [2] Hort J, Brozek G, Mares P, et al. Cognitive functions after pilocarpine —induced status epilepticus : changes during silentperiod precede appearance of spontaneous recurrent seizures [J]. Epilepsia , 1999 , 40 : 1177 [3] Michael P, Honchar JW, Olney WR, et al. Systimic cholinergicagents induce seizures and brain damage in lithium - treated rats [J ] . Science , 1983 , 220 : 323 [4] Glien M, Brandt C, Pot schka H, ​​et al. Repeated low-dose treatment of rats with pilocarpine : low mortality but highproportion of rats developing epilepsy [J ] . Epilepsy Res , 2001 , 46 : 111 [5] Sato M, Racine RJ, Mc Intyre DC. Kindling : basic mechanisms and clinical validity [J ] . Electroencephalography and clinical Neurophysiology , 1990 , 76 : 459 [6] Cavalheiro EA , Santos NF , Priel MR. The pilocarpine model of epilepsy in mice [J ] . Epilepsia , 1996 , 37 : 1015 [7] Jope RS , Morriset t RA , Snead OC. Characterization of lithium potentiation of pilocarpine-induced status epilepticus in rats [J ] . Exp Neurol , 1986 , 91 : 471 [8] Isokawa M. Remodeling dendritic spines of dentate granule cells in temporal lobe epilepsy patients and the rat pilocarpine model [J] . Epilepsia , 2000 , 41 : S14 |