CAJ | 학술논문

目的：观察雌激素对大鼠脑缺血再灌注后血脑屏障（ blood-brain barrier,BBB)的通透性、Occludin表达的影响,探讨雌激素在脑缺血中的作用。方法随机将去势雌性大鼠分为假手术组、模型组、雌激素预处理组,选取缺血再灌后4 h,24 h,3 d 3个时间点作为观察点,对各个时间点脑水肿情况、Occludin蛋白表达、血脑屏障通透性改变进行考察分析,并选取24 h和3 d作BBB超微结构电镜观察,脑水肿改变情况采用脑含水量百分数测定；蛋白质表达采用western blot方法；血脑屏障通透性改变采用伊文思蓝（EB)比色法。结果与假手术组比较,局灶性脑缺血再灌4 h模型组大鼠脑组织含水量及EB含量均增加（P<0.05),随缺血再灌时间延长,脑组织含水量、脑组织EB含量持续增加,至24 h,达到高峰（P<0.01),与同时间点模型组比较,各治疗组大鼠脑组织含水量、EB含量均有不同程度降低（P<0.05或P<0.01),以24 h组降低最为显著（P<0.01)。电镜观察雌激素预处理组较模型组同时间点比较BBB TJ 开放减轻,星形胶质细胞足突及毛细血管管周水肿较轻,以3 d组显著。 Western blot检测Occludin蛋白表达,发现模型组4 h 时Occludin蛋白表达较假手术组减弱,但无显著性差异（P>0.05),24 h组Occludin蛋白表达较假手术组减弱,有显著性差异（P<0.05),3 d组Occludin蛋白表达进一步减弱,有明显差异（P<0.01),雌激素组4 h时Occludin蛋白表达较同时间点模型组比较无显著性差异（P>0.05),雌激素24 h及3 d组Occludin蛋白表达较同时间点模型组比较均升高,有显著性差异（P<0.05)。结论局灶性脑缺血大鼠动物血脑屏障超微结构可见紧密连接发生断裂,内皮细胞内小泡数量增加及星形胶质细胞足突肿胀,可能是大鼠局脑缺血时血管源性脑水肿的重要因素。大鼠局灶性脑缺血,随缺血再灌时间延长,紧密连接相关蛋白occludin的表达明显下降,提示occludin在调节紧密连接通透性变化的过程中有重要作用。雌激素上调紧密连接Occludin蛋白的表达,有可能是其维护血脑屏障完整性减轻脑水肿的机制之一。目的：觀察雌激素對大鼠腦缺血再灌註後血腦屏障（ blood-brain barrier,BBB)的通透性、Occludin錶達的影響,探討雌激素在腦缺血中的作用。方法隨機將去勢雌性大鼠分為假手術組、模型組、雌激素預處理組,選取缺血再灌後4 h,24 h,3 d 3箇時間點作為觀察點,對各箇時間點腦水腫情況、Occludin蛋白錶達、血腦屏障通透性改變進行攷察分析,併選取24 h和3 d作BBB超微結構電鏡觀察,腦水腫改變情況採用腦含水量百分數測定；蛋白質錶達採用western blot方法；血腦屏障通透性改變採用伊文思藍（EB)比色法。結果與假手術組比較,跼竈性腦缺血再灌4 h模型組大鼠腦組織含水量及EB含量均增加（P<0.05),隨缺血再灌時間延長,腦組織含水量、腦組織EB含量持續增加,至24 h,達到高峰（P<0.01),與同時間點模型組比較,各治療組大鼠腦組織含水量、EB含量均有不同程度降低（P<0.05或P<0.01),以24 h組降低最為顯著（P<0.01)。電鏡觀察雌激素預處理組較模型組同時間點比較BBB TJ 開放減輕,星形膠質細胞足突及毛細血管管週水腫較輕,以3 d組顯著。 Western blot檢測Occludin蛋白錶達,髮現模型組4 h 時Occludin蛋白錶達較假手術組減弱,但無顯著性差異（P>0.05),24 h組Occludin蛋白錶達較假手術組減弱,有顯著性差異（P<0.05),3 d組Occludin蛋白錶達進一步減弱,有明顯差異（P<0.01),雌激素組4 h時Occludin蛋白錶達較同時間點模型組比較無顯著性差異（P>0.05),雌激素24 h及3 d組Occludin蛋白錶達較同時間點模型組比較均升高,有顯著性差異（P<0.05)。結論跼竈性腦缺血大鼠動物血腦屏障超微結構可見緊密連接髮生斷裂,內皮細胞內小泡數量增加及星形膠質細胞足突腫脹,可能是大鼠跼腦缺血時血管源性腦水腫的重要因素。大鼠跼竈性腦缺血,隨缺血再灌時間延長,緊密連接相關蛋白occludin的錶達明顯下降,提示occludin在調節緊密連接通透性變化的過程中有重要作用。雌激素上調緊密連接Occludin蛋白的錶達,有可能是其維護血腦屏障完整性減輕腦水腫的機製之一。
목적：관찰자격소대대서뇌결혈재관주후혈뇌병장（ blood-brain barrier,BBB)적통투성、Occludin표체적영향,탐토자격소재뇌결혈중적작용。방법수궤장거세자성대서분위가수술조、모형조、자격소예처리조,선취결혈재관후4 h,24 h,3 d 3개시간점작위관찰점,대각개시간점뇌수종정황、Occludin단백표체、혈뇌병장통투성개변진행고찰분석,병선취24 h화3 d작BBB초미결구전경관찰,뇌수종개변정황채용뇌함수량백분수측정；단백질표체채용western blot방법；혈뇌병장통투성개변채용이문사람（EB)비색법。결과여가수술조비교,국조성뇌결혈재관4 h모형조대서뇌조직함수량급EB함량균증가（P<0.05),수결혈재관시간연장,뇌조직함수량、뇌조직EB함량지속증가,지24 h,체도고봉（P<0.01),여동시간점모형조비교,각치료조대서뇌조직함수량、EB함량균유불동정도강저（P<0.05혹P<0.01),이24 h조강저최위현저（P<0.01)。전경관찰자격소예처리조교모형조동시간점비교BBB TJ 개방감경,성형효질세포족돌급모세혈관관주수종교경,이3 d조현저。 Western blot검측Occludin단백표체,발현모형조4 h 시Occludin단백표체교가수술조감약,단무현저성차이（P>0.05),24 h조Occludin단백표체교가수술조감약,유현저성차이（P<0.05),3 d조Occludin단백표체진일보감약,유명현차이（P<0.01),자격소조4 h시Occludin단백표체교동시간점모형조비교무현저성차이（P>0.05),자격소24 h급3 d조Occludin단백표체교동시간점모형조비교균승고,유현저성차이（P<0.05)。결론국조성뇌결혈대서동물혈뇌병장초미결구가견긴밀련접발생단렬,내피세포내소포수량증가급성형효질세포족돌종창,가능시대서국뇌결혈시혈관원성뇌수종적중요인소。대서국조성뇌결혈,수결혈재관시간연장,긴밀련접상관단백occludin적표체명현하강,제시occludin재조절긴밀련접통투성변화적과정중유중요작용。자격소상조긴밀련접Occludin단백적표체,유가능시기유호혈뇌병장완정성감경뇌수종적궤제지일。
Objective To observe the effect of estrogen on BBB permeability,occludin expression after ischemia-reperfusion in rats,and to make a further investigation on the role of estrogen in cerebral ischemia. Methods Ovariectomized rats were randomly divided into sham-operated group,model group,and estrogen pretreatment group. 4 h,24 h,3 d after ischemia-reperfusion were selected as different observation points,and changes of edema,occluding expression,and blood-brain barrier permeability of the 3 points in time were observed. BBB ultra-structure electron microscope observation was made at 24 h and 3 d after ischemia-reperfusion. Changes in cerebral edema were measured by brain water content percentage;protein expressions were measured by Western blot;and BBB permeability was measured by Evans blue as-say. Results Compared with the sham group,brain tissue water content and EB content in model group both increased 4 h after ischemia-reperfusion (P<0. 05),and they keep increasing as time goes by and finally reaching the peak (P<0. 01). Compared with the model group at the same time point,brain tissue water content and EB content in estrogen pretreatment group decreased in different degrees (P<0. 05 or P<0. 01),and it was most significant at the time point of 24 h after ischemia-reperfusion (P<0. 01). Compared with model group,through electron microscope observation,ia was displayed that BBB TJ's open was reduced in estrogen pretreatment group,astrocyte foot process and capillary tube edema were lighter,and it was significant at the time point of 3 d after ischemia-reperfusion. Western blot detection of occludin protein expression found that it was lower in the model group compared with the sham group at 4 h after ischemia-reperfusion,but there was no significant difference (P>0. 05). 24 h after ischemia-reperfusion,the occludin expression were weaker than that in the sham surgery group with a significant difference (P<0. 05),and it keep weakening with a significant difference 3 d after ischemia-reperfusion (P<0. 01). In estrogen group,there was no significant difference compared with the model group in terms of occludin expression at 4 h after ischemia-reper-fusion (P>0. 05). In estrogen group,there was significant difference in occludin protein expression at 24 h and 3 d after ischemia-reperfusion compared with model group at the same time point (P<0. 05). Conclusion BBB ultrastructure disclose TJ was broke and vesicles within EC was increased and astrocyte cell foot process was swelling in MCAO model,it might be the vasogenic brain edema pathological basis for MCAO. In MCAO animal model,with ischemia-reperfusion time increasing,TJ protein occludin expression significantly decreased,it suggests that occludin plays an important role in the regulation of TJ permeability. Estrogen increases has a very close relationship with occludin ex-pression,and it may be one of the mechanisms of protecting BBB integrity and lessening cerebral edema.