银杏酮酯速释微丸和缓释微丸对脑缺血再灌注大鼠缺氧损伤的影响

Effects of immediate-release- and sustained-release pellets of Ginkgo biloba extract for cerebral ischemia injury in rats with hypoxia

目的探讨银杏酮酯(Ginkgo biloba extract)缓释微丸和速释微丸对大鼠大脑中动脉栓塞(middle cerebral artery occlusion,MCAO)所致缺血损伤的神经保护作用及释药速度对药效的影响。方法 36只雄性SD大鼠分为速释微丸组、缓释微丸组、模型对照组及假手术组。除假手术组,其他组大鼠采用插线法制备MCAO。灌胃7 d后,采用5分行为指标评分,记录脑质量,采用TTC染色测定脑梗死范围。取脑组织测定一氧化氮(NO)、一氧化氮合成酶(NOS)、乳酸(LD)及乳酸脱氢酶(LDH)的含有量及活性。结果速释微丸组大鼠的行为指标评分、脑指数、NO含有量与模型组相比有显著性差异,LD含有量具有极显著性差异;而缓释微丸组与模型组相比,其NO含有量,诱导型一氧化氮合酶(i NOS)、总一氧化氮合酶(TNOS)、LDH活性具有显著性差异,行为指标评分、脑指数和LD含有量具有极显著性差异。缓释微丸组和速释微丸比较,脑梗死率具有显著性差异,缓释微丸相比速释微丸组效果更好。结论对于脑缺血再灌注的防治,银杏酮酯可能制备成缓释制剂效果更理想。

AIM To investigate the neuroprotective effects of immediate-release- and sustained-release pellets of Ginkgo biloba extract（ GBE） against acute middle cerebral artery occlusion（ MACO） in rats. METHODS Thirty-six male SD rats were divided into immediate-release pellets group,sustained-release pellets group,model group and sham-operated group. All groups except the sham-operated group underwent right MACO using an intraluminal thread. After intragastric gavage for seven days,the neurologic score,infarct size measured by TTC staining,brain weight,nitric oxide（ NO）,nitric oxide synthase（ NOS）,lactic acid（ LD） and lactate dehydrogenase（ LDH） in brain were evaluated for different groups. RESULTS Compared with the model group,the neurologic score,cerebral index and LD level showed statistical differences,and NO level had significant statistical differences in rats pre-treated by immediate-release pellets of GBE. While in rats pretreated by sustained-release pellets of GBE,the levels of NO and LDH,the activities of i NOS and TNOS showed the statistical differences,the neurologic score,cerebral index and LD level had significant statistical differences compared with the model group. Comparing between the two treated groups,the cerebral infarction rate in sustained-release pellets of GBE group performed better than that in the immidiate-release pellets of GBE group. CONCLUSION GBE sustained-release pellets would be better than GBE immediate-release pellets when used for protecting and treating cerebral ischemiareperfusion injury.