镧示踪甘露醇开放大鼠血脑屏障机制的实验研究.pdfVIP

镧示踪甘露醇开放大鼠血脑屏障机制的实验

研究

【摘要】目的：研究甘露醇高渗性开放大鼠血脑屏障

（blood-brainbarrier,BBB）的机制。方式：采纳静脉内注射mL2%

硝酸镧作为外源性示踪剂，10min后颈内动脉注射37℃20%甘露醇

mL开放SD大鼠BBB，通过外源性硝酸镧透射电镜示踪法观看BBB超微

结构改变，研究热点区域包括注射侧与对侧大脑皮层。结果：实验组

（注射20%甘露醇组），镧（La3+）在同侧大脑半球皮质区充填并通过

脑血管内皮细胞（BMECs）之紧密连接（TJs）至血管腔外-脑间质裂隙

内，对侧大脑半球皮质区局部有La3+渗出至基底膜（BM）；对照组那

么完全封锁于血管腔内（Plt;）；各部位胞浆内均无La3+。结论：20%

甘露醇通过开放TJs致使BBB通透性增高，同侧大脑半球强于对侧大

脑半球。

【关键词】BBB通透性超微结构甘露醇

AbstractObjective：Toinvestigatethemechanismsof

osmoticBBBdisruptioninducedbyintra-carotidarteryinfusion

ofmannitol.Methods：MaleSDratsunderwentintravenous

administrationofmL2%lanthanumnitrateover2minutes

later,warm20%mannitolwasintra-arteriallyinfusedatarate

ofmL/secondover30interestingspotsincludedcortical

tissueswithintheipisilateralandoppositehemisphereofthe

brainrespectively.TheultrastructureofBBBwasobservedby

lanthanumnitrate-tracingtransmissionelectronic：Inthe

braintissuesofcontrolgroup,La3+isexcludedfromTJs.

However,forthetrialgroup,TJsintheoppositehemisphereof

thebrainwerecompletelyinfiltratedwithLa3+and

extravasationtothebasementmembranewasseenincertainsites

ofthecapillaries;La3+penetratedthecellulargapsof

endotheliaandseepedinthebasementandinterstitialspaces

inipisilateralhemisphereofthebrain（Plt;）.NoLa3+wasseen

inthecytoplasmofcerebralmicrovesselendothelialcellsboth

intrialandcontrolgroups.Conclusion：OpenedTJsresultin

theenhancedpermeabilityofBBBinducedbyintra-arterial

infusionofmannitol.

KeywordsBBB；Permeability；Ultrastucture；Mannitol