弥散加权磁共振扫描评价川芎嗪对局灶性脑缺血损伤保护作用的实验研究

目的 用弥散加权磁共振技术评价川芎嗪(tetramethylpyrazine，TMP)对大鼠局灶性脑缺血损伤的保护作用。方法 采用局灶性脑缺血模型，将16只雄性SD大鼠，随机分为对照组和实验组(TMP组)，每组8只，分别在缺血前腹腔注射生理盐水和TMP。行弥散加权(diffusion—weighted imaging，DWI)磁共振(magnetic resonance imaging，MRI)系列扫描，观察缺血后1、2、6、12、24h脑梗死灶变化，以及24h三苯四氯氮唑(TTC)染色的脑梗死容积。结果TMP组各时间点DWI—MRI扫描脑梗死容积明显小于对照组(P<0．01)。与1h点相比，对照组脑梗死容积在栓塞后2、6、12、24h分别扩大13．3％、29．7％、50．3％、57．3％，TMP组扩大9．9％、21．3％、37．1％、40．5％。缺血24hTTC测算的脑梗死容积大于DWI—MRI测算的脑梗死容积。结论 缺血前注射TMP对大鼠局灶性脑缺血损伤具有作用；采用DWI—MRI扫描动态观察脑缺血灶的演变过程和评价脑保护措施的作用，具有重要的意义。

Experimental Study of Evaluation on Neuroprotective Effect for Tetramethylpyrazine against Focal Cerebral Ischemic Injury with Diffusion-weighted Magnetic Resonance Imaging

OBJECTIVE: To evaluate the neuroprotective effect of tetramethylpyrazine (TMP) against focal cerebral ischemic injury in rats with diffusion-weighted magnetic resonance imaging (DWMRI). METHODS: Rat models of focal cerebral ischemic injury were established in 16 male SD rats. They were randomly divided into the TMP group and the control group, eight in each group, and pretreated with TMP and normal saline respectively before modeling. Change of infarcted cerebral focus was observed with DWMRI at 1, 2, 6, 12 and 24 hrs after infarction, and the infarction volume (IV) at 24 hrs after modeling was estimated by triphenyltetrazolium chloride (TTC) stain. RESULTS: The IV in all time points observed in the TMP group with DWMRI was significantly smaller than that in the control group (P<0.01). Compared with that at 1 hr after infarction, in the control group at 2, 6, 12 and 24 hrs after modeling, the IV enlarged by 13.3%, 29.7%, 50.3% and 57.3% respectively, while that in the TMP group 9.9%, 21.3%, 37.1% and 40.5% respectively. The cerebral IV estimated by TTC stain 24 hrs after modeling was larger than that estimated by DWMRI. CONCLUSION: TMP pretreatment before modeling was effective in protecting brain against cerebral ischemic damage in rats. DWMRI dynamic scanning observation has important significance in observing the cerebral ischemic developing process and evaluating the effectiveness of brain protective measures.