益气活血对脑缺血再灌注沙土鼠脑膜微循环的作用

背景:急性脑梗死药物治疗的关键在于尽早有效地改善脑部供血,及时有效地抢救缺血半暗带的神经细胞,最大限度地缩小梗死灶。目的:观察中医益气活血法对沙土鼠脑缺血再灌注后脑膜微循环的作用。设计:随机对照动物实验。单位:上海市长征医院闸北分院。材料:实验在海军医学研究所(全军重点实验室)完成。实验动物选择蒙古种健康6月龄沙土鼠22只,随机数字表法分为药物组和对照组,每组11只。方法:常规麻醉,取俯卧位固定后正中线开颅窗,暴露软脑膜,术后颅窗用浸有人工脑脊液的药棉覆盖。取仰卧位,颈腹侧正中切口,分离暴露两侧颈总动脉,无损伤显微动脉夹双重夹闭两侧颈总动脉,显微镜下观察所夹闭血管远端血流中断。夹闭30min后,松解血管夹,使脑血流再灌注,药物组即以黄芪注射液0.4mL(含生药0.8g)、复方当归注射液0.3mL(含当归、川芎、红花生药各0.09g)、丹参注射液0.3mL(含生药0.45g)腹腔注射,对照组在相同部位注入等量生理盐水。激光微循环显微镜及其电视录像系统通过颅窗分别量化观察两组实验动物颈总动脉阻断前、阻断后再灌注以及注射药物后120min期内软脑膜微循环的变化。主要观察指标:脑缺血再灌注前后各组沙土鼠脑膜微循环的变化以及细动静脉血流速度的比较。结果:在实验过程中无动物死亡,全部进入结果分析。①颈动脉阻断后,两组实验动物均可见脑膜微血管明显收缩,部分血管闭塞,部分Ⅰ级细动脉及Ⅲ级以内细静脉出现血小板、红细胞等血液有形成分沉积粘附,形成微小血栓,出现大片状缺血区,血流速度明显减慢,红细胞出现中度至重度聚集,血液中白细胞数目增多,微血管周围明显渗出。颈动脉再灌注后,细动脉、静脉可出现粗细不均,细静脉Ⅰ,Ⅱ级血管内在脑缺血时形成的血栓凝块不易被血流疏通,红细胞中度聚集,白细胞数多,有时可见白色微小血栓,微血管周围渗出现象无明显改观。药物组经腹腔注射益气活血药后,细动、静脉开放,血液速度加快,血流量明显增加,细静脉沉积物开始减少,血栓凝块逐渐疏松,栓塞处疏通,红细胞呈轻度聚集或正常,缺血区血供较再灌流后进一步改善,微血管周围渗出现象逐渐减轻甚至消退。对照组未见明显改变。②药物组动物细动脉流速1.04～1.50mm/s,明显高于对照组,差异有显著性意义(P<0.05～0.01)。③药物组动物细静脉流速0.96～1.12mm/s,明显高于对照组,差异有显著性意义(P<0.05～0.01)。结论:益气活血法对沙土鼠脑缺血再灌注后脑膜微循环的作用确切,其直接作用与加快血流速度,扩张细动脉、细静脉管径,改善大脑血供等有关。

Effects of supplementing qi and activating blood circulation on piamatral microcirculation in gerbils with cerebral ischemic reperfusion

BACKGROUND: The key point in the treatment of acute cerebral infarction lies in inproving the blood supply of brain effectively as soon as possible as well as rescue ischemic and half diazonal nerve cells, so as to contract the local of infarction as great as possible.OBJECTIVE: To observe the effect of traditional treatment of cerebral piamatral microcirculation in gerbil with cerebral ischemic reperfusion injury by supplementing qi and activating blood circulation.DESIGN: Contrast animal experiment at random.SETTING: Zhabei Branch of Shanghai Changzheng Hospital.MATERIALS: The experiment was performed in the Institute of Naval Medicine (key laboratory of the whole army). Twenty-two healthy Monglian gerbils of clean grade (six months old) were selected and randomly divided into medicine group and control group with 11 gerbils in each group.METHODS: Animals were routinely anaesthetized and fixed in prone position to open the cranium window in median line and expose the pia mater. The cranium window was protected by being covered with a cotton ball containing artificial cerebrospinal fluid (ACSF) after operation. Gerbils were fixed in dorsal position with an median incision made in the lateral cervical nucleus to isolate and expose bilateral common carotid artery (CCA). The bilateral CCA were occluded by atraumatic micro-bulldog clamp, and the occluded blood flow in the distal end was observed under the microscope. Thirty minutes after occlusion of bilateral CCA, the vascular clamp was unclamped to recover the cerebral blood reperfusion. Gerbils in the medicine group were abdominally injected with 0.4 mL of Huangqi injection (containing 0.8 g of crude drug), 0.3 mL of compound Danggui injection (containing Danggui, Chuanqiong and Honghua, 0.09 g for each)and 0.3 mL of Danshen injection (containing 0.45 g of Shengyao). Animals in the control group were abdominally injected with same-volume of normal saline. The changes of pial microcirculation were quantitatively observed in two groups through cranium window respectively before blockage, at the reperfusion after blockage as well as in 120 minutes after injection by laser microcirculation microscope and the TV video system.MAIN OUTCOME MEASURES: The changes of piamatral microcirculation as well as comparison in venous blood flow velocity in gerbils of each group before and after ischemic reperfusion.RESULTS: All gerbils were involved in the analysis of results with no animal died in the experiment.①When the CCA of animals in the two groups were blocked, obvious contraction of piamatral microcirculation was seen and partial blood vessels were blocked up. Platelet and red blood cells etc.adhered to the arteriolae of grade Ⅰ and veinules below grade Ⅲ with microthrombus formed and large ischemic area appeared. The blood flow rate was obviously slowed down. Moderate and severe aggregations were found in red blood cells, and the white blood cells were significantly increased.There was obvious exudation in the periphery of microvessels. After CCA reperfusion, the arteriolae and veinule were in different thickness, and the thrombus in veinule of grade Ⅰ and Ⅱ formed in the cerebral ischemia were difficult to be removed by blood flow. Red blood cell moderately aggregated, and the number of white blood cells greatly increased. White small thrombus could be seen sometimes, while the exsudation in the periphery of microvessel was not significantly ameliorated. Great changes were found in gerbils of the medicine group after abnormal injection of supplementing qi and activating blood circulation medicine: almost all arteriolae and venulae were opened, and the rate of blood flow was accelerated with the blood flow rate remarkably increased. Deposit in the venulae began to decreased, and the thrombus was gradually dissolved. Red blood cells were moderately aggregated or normal. Blood flow in ischemic spot was improved significantly than that after reperfusion. The exudation in the periphery of microvessels was gradually lessened even dissolved. However,no obvious change was found in gerbils of the control group. ②The blood flow rate of arteriole in the medicine group was 1.04-1.50 mm, which was obviously higher than that in the control group with significant differences (P ＜ 0.5-0.01).③The blood flow rate of veinule in the medicine group was 0.96-1.12 mm/s, which was remarkably higher than that in the control group with marked differences (P ＜ 0.05-0.01).CONCLUSION: The effect on piamatral microcirculation of gerbil with cerebral ischemic reperfusion by supplementing qi and activating blood is exact, which is directly related with accelerated blood flow rate, expanded veinule and arteriolae as well as ameliorated blood-supply of brain.