局灶性脑缺血再灌注损伤核心区及半暗带的组织学定位

目的观察局灶性脑缺血1h和2h,再灌注至24h后的组织损伤及核心区和半暗带的组织学定位。方法利用大鼠局灶脑缺血模型及HE染色和图像分析,对损伤进行定量。结果缺血核心区表现为脑组织的完全坏死,半暗带位于核心区周围,表现为选择性神经元死亡,其中缺血1h组的病变变异较大。缺血2h组的皮质、纹体和半球核心区及其半球病变明显大于缺血1h组(P依次<0.02、0.01、0.01和0.05)。依据大鼠脑立体定位图谱,对缺血2h和缺血1h的皮质、纹体核心区和半暗带进行了组织学定位。结论脑缺血损伤时,皮质和纹体均存在核心区和半暗带,其定位相对恒定,为应用脑微透析方法探讨脑缺血损伤机制,提供了组织学依据。

Histological location of core and penumbra of cortex and striatum underwent focal cerebral ischemia and reperfusion

Objective To observe the pathological changes of cerebral ischemia and locate the histologicl positions of microdialytic probe i n core and penumbra of cortex and striatum.Methods The rat model of local cere bral ischemia by occluding middle cerebral artery was used.The rats underwent 1or2h of ischemia and then reperfusion for23h or22h,rspectively.The is c hemic damage was observed by HE staining and analyzed quanititatively by image a nalysis.Results The cores in the groups of1h or2h ischemia were dis tributed in the areas supplied by middle cerebral artery and the penumbra was lo cated on the surround ing areas of cores.The core displayed tissure necrosis completely while the penum bra dis played selective neu ron death.The volumes of cores in cortex and striatum,and hemisphere dam age in the groups of2h ischemia were s ignificantly larger than that in the group of1h ischemia(P<0.02?0.01 ?0.01and0.05,respectively),but the volumes of penumbras were no sta tistical difference.Accord ing to the stereotaxic atlas of the rat brain,we d etermined the locations of microdialytic probes in core and penum bra in cortex and striatum underwent 2h and1h ischemia.Conclusion The degree of is chemic d amdge is related to the duration of ischemia and penumbra is existed in cortex a nd striatum dur ing local cerebral ischemia.The positions of microdia lytic pro bes in core and penumbra of cortex or stria tum will provide the evidence to uti lize the cerebral microdialysis to explore the mechanisms of cerebral is chemi a,especialy the late brain damage.