摘要
目的 探讨大鼠脑缺血再灌注后两环加氧酶异构体 (COX 1和COX 2 )基因表达的变化及天然血小板活化因子 (PAF)受体拮抗剂海风藤新木脂素复合物和银杏内酯对两酶表达的影响。 方法 应用RT PCR技术 ,检测大脑中动脉线栓闭塞再通不同时相大脑中动脉供血区皮质COX 1与COX 2基因的表达水平。 结果 缺血及药物预处理对COX 1mRNA表达水平均无显著影响。单纯缺血 90min时 ,缺血皮质COX 2mRNA表达含量无明显变化 ,密度比值为 0 2 7± 0 0 5 ;再灌注 6h显著升高 ( 0 83± 0 12 ) ,12h最强 ( 1 2 2± 0 19) ,至 4 8h仍较假手术对照组高 ( 0 4 9± 0 0 8)。两种PAF受体拮抗剂均能显著抑制缺血再灌注 12hCOX 2基因的表达增高 ( 0 5 8± 0 11和 0 6 8±0 13)。 结论 脑缺血再灌注可诱导COX 2基因表达增强 ;PAF是COX 2基因表达的上游信号分子 ,抑制COX 2基因高表达可能是海风藤新木脂素复合物及银杏内酯的脑保护分子机制之一。
Objective To study the effects of natural platelet activating factor(PAF) receptor antagonist (kadsurenin mixture and ginkgolide B)on cyclooxygenase 1 (COX 1) and cyclooxygenase 2 (COX 2) messenger RNA (mRNA) expression in rat brain tissue during ischemia reperfusion Methods Fourty elderly Wistar rats were divided into eight groups: sham operated control group, simple ischemia for 90 min group, 6 h , 12 h , 24 h , 48 h reperfusion groups, kadsurenin mixture treated and ginkgolide treated groups After right middle cerebral artery occluded, rats underwent ischemia for 90 minutes, then reperfusion was allowed for different time as mentioned above before decapitation Reverse transcription polymerase chain reaction (RT PCR) was applied to evaluate the COX 1 and COX 2 mRNA expression levels in rat brain tissue of ischemia reperfusion Results RT PCR analysis revealed that the levels of mRNA of COX 2 of 6 h , 12 h , 24 h and 48h reperfusion groups were all significantly higher than the sham operated control group's(density ratio:0 27±0 05). The climax of the levels of COX 2 mRNA was at 12 h(1 22±0 19) Both PAF receptor antagonist inhibited the increased expression of COX 1 mRNA(0 58±0 11 vs 0 68±0 13)in 12 h reperfusion group significantly Conclusions The cerebral ischemia reperfusion can induce the enhancement of COX 2 mRNA expression PAF is an upper stram signal in the expression of COX 2 mRNA Reducing the expression of COX 2 mRNA might be one of the neuroprotective machnism of two natural PAF receptor antagonists
出处
《中华老年医学杂志》
CAS
CSCD
北大核心
2004年第4期250-252,共3页
Chinese Journal of Geriatrics
基金
国家自然科学基金资助项目 (3 9870 2 60 )
