高颅压后兔大脑中动脉血流速度对脑自由基和病理形态的影响

Effect on free radical reaction and pathomorphism of brain due to the changes of the flow velocities of middle cerebral artery after acute increased intracranial pressure in rabbits.

应用经颅多普勒(TCD)超声技术,观察了30只兔急性颅内压增高(AIIP)后大脑中动脉血流速度(FVmca)变化引起兔脑组织自由基反应及对兔脑病理形态的影响。结果发现,兔AIIP后FVmca频谱中舒张期流速(Vd)降为零后不同时间,自由基反应和病理形态变化也不同。Vd为零持续6小时,脑匀浆超氧化物歧化酶(SOD)和脂质过氧化物(LPO)变化不大;光镜下形态学未见明显改变。持续12小时,SOD下降,LPO升高;细胞及血管周围间隙扩大。持续13～24小时,SOD下降和LPO升高显著;可见脑实质内出血,锥体细胞核固缩,胶质细胞增生等。说明AIIP后造成的脑不完全缺血时间愈长,自由基反应强度愈烈,病理改变愈多。提示TCD可用于估价脑损害的程度。

The flow velocities of middle cerebral artery(FVmca) were studied by transcranial Doppler(TCD) ultrasonography and the free radical reac-tion of brain and pathomorphism changes were alsostudied in 30 rabbits with acute increased intracra-nial pressure (AIIP). The results showed that whendiastolic velocity (Vd) = 0 lasting for 6hrs, therewere no changes in free radical reaction and patho-morphism of brain tissue, while lasting for 12hrs,superoxide dismutase(SOD) decreased and lipoper-oxide (LPO) increased (P<0. 05); a bit of cerebralischemia was found by optical microscope. While13 -- 24hrs, SOD decreased and LPO increased re-markably (P<0. 01), a lot of cerebral edema andcerebral ischemia were seen. This study showed thatthe longer VD=0 lasted the more cerebral lesionwas, and TCD may be useful to assess the degree ofcerebral damage.