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

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。

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.

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.