摘要
目的探讨天冬氨酸特异性半胱氨酸蛋白酶-3(caspase-3)在惊厥性脑损伤发病机制中的作用及银杏叶提取物对脑损伤的可能保护机制。方法将20日龄健康SD大鼠108只随机分为3组:对照组、惊厥组及银杏叶提取物干预组。通过三氟乙醚反复吸入制备大鼠惊厥模型。干预组在每次惊厥后立即腹腔注射银杏叶提取物50 mg/kg,12 h后再重复注射1次,其他两组注射等量生理盐水。各组动物于末次惊厥后1、3和7 d采用免疫组化法检测海马组织中caspase-3蛋白表达,采用逆转录-聚合酶链反应(RT-PCR)方法检测海马组织中caspase-3 mRNA表达。结果末次惊厥后1、3和7 d海马caspase-3的蛋白及mRNA表达均较对照组显著升高,3 d时达峰值(P均<0.01)。银杏叶提取物干预组各时间点海马caspase-3的蛋白及mRNA表达均较惊厥组显著下调(P<0.05或P<0.01)。结论大鼠反复惊厥后海马caspase-3表达显著增高,提示caspase-3参与了惊厥性脑损伤的病理过程。银杏叶提取物能下调惊厥后海马caspase-3的异常表达,提示其对惊厥性脑损伤的保护机制可能与抑制海马caspase-3异常表达有关。
Objective To investigate the effects of Ginkgo biloba （银杏叶） extract on the expression of caspase-3 in the hippocampus of the rats following recurrent seizures, the role of caspase-3 in the brain injury induced by seizures and the possible protective mechanism of Ginkgo biloba extract against brain injury. Methods One hundred and eight Sprague-Dawley （SD） rats, twenty-day-old, were divided randomly into three groups： the control group, the seizure group and the Ginkgo biloba extract treatment group. Seizures models in rats were produced by consecutive inhalation of flurothyl daily for six days. The rats in the Ginkgo biloba extract treatment group received 50 mg/kg of the Ginkgo biloba extract through intra-abdominal injection immediately after every seizure, and after 12 hours another injection was repeated, while the rats in seizure group and control group received volume-matched saline through intra-abdominal injections. Brain tissue was sampled at different time points （1 day, 3 days, 7 days） after last seizure. The expression of caspase-3 protein in the hippocampus was detected by immunohistochemistry, and the expression of caspase-3 mRNA was measured by reverse transcription-polymerase chain reaction （RT-PCR）. Results The caspase-3 protein and easpase-3 mRNA levels at the time points of post-selzure 1, 3, 7 days in the hippoeampus of the rat pups in seizure group were much higher than those in control group, while they were highest on the post-seizure 3rd day （all P〈0. 01）. In Ginkgo biloba extract treatment group, the expression of caspase-3 mRNA and caspase-3 protein in the hippocampus at different time points significantly lower than those at corresponding points in seizure group （P 〈 0. 05 or P 〈 0. 01）. Conclusion Ginkgo biloba extract can down-regulate the abnormal expression of caspase-3 in the hippocampus after rat repeated seizures. The suppression of the abnormal levels of caspase-3 in the hippocampus is probably related to the protective effects of Ginkgo biloba extract on the brain injury induced by seizures.
出处
《中国中西医结合急救杂志》
CAS
2008年第2期81-84,F0002,共5页
Chinese Journal of Integrated Traditional and Western Medicine in Intensive and Critical Care
基金
湖南省科技计划基金资助项目(06sk3030)
