大鼠局灶性脑梗死皮层血流量和c-fos表达的实验研究

A Study of Cerebral Blood Flow and c-fos Expression Following Focal Cerebral Infarction

目的探讨大鼠局灶性脑梗死后皮层血流量和c-fos表达的变化。方法光化学法诱导大鼠局灶性脑梗死模型,应用激光多普勒微循环测量仪检测局灶性脑梗死后各时间点坏死区和半暗带皮层血流量,采用SABC免疫组化法检测局灶性脑梗死后各时间点c-fos阳性反应的表达情况。结果脑梗死后坏死区皮层血流量呈波浪样改变,3h降至最低,为正常血流量的(9.36±1.72)%,6h后回升,12h达高峰,为正常的(31.18±1.44)%,24～48h血流量再度下降,与3h相比无显著性差异(P>0.05)。半暗带皮层血流量6h降至最低,为正常皮层血流量的(30.88±7.11)%,9～48h呈上升趋势,至48h血流恢复至正常的(91.90±4.56)%,较其它组有显著性差异(P<0.05)。c-fos在脑梗死发生30min时半暗带区即有大量蛋白表达,并随时间的延长表达量相应增加,直至6h达表达高峰;在梗死后3h整个同侧皮层出现c-fos的弥漫性表达,6h发现梗死对侧大脑皮层亦有表达。观察9h后各个时间点的表达量逐渐减少,且只限于梗死的半暗带区。在坏死区均未见c-fos表达。结论局灶性脑梗死后皮层血流量和c-fos的表达具有明显的时间和空间的变化规律。

Objective To explore the change of cerebral blood flow and c-fos expression following focal cerebral infarction. Methods To establish the model of focal cerebral infarction based on the principle of photochemical initiation of thrombosis. Laser Doppler Flowmetry measured cerebral blood flow in ischemic core and penumbra. c-fos positive cells were observed by SABC immunohistochemical technique at different time points. Results Cerebral blood flow in ischemic core looked like waves. It decreased to the minimum after 3 hours which was 9.36%±1.72% of normal cerebral blood flow. But after 6 hours it began to increase. Cerebral blood flow increased to the maximum at 12 hours which was 31.18%±1.44% of normal flow. It reduced after 24 hours. There was no significant differences at 24, 36 and 48 hour points compared with that at 3 hours. Cerebral blood flow penumbra decreased to the minimum at 6 hours which was 30.88%±7.11% of normal . From time point of 9h to 48 hours, cerebral blood flow in penumbra increased gradually. At 48 hours 91.90%±4.56% of normal cerebral blood flow was recovered, there was significant difference compared with that of others. c-fos positive cells expressed generously at the point 30min. The expression was increasing with time. The high peak of expression occurred at 6 hours and all two cerebral hemispheres expressed. From the time point of 9 hours, the expression of c-fos positive cells decreased gradually. The expression occurred only in penumbra. At all time points there was no expression in ischemic core. Conclusion Cerebral blood flow and expression of c-fos following focal cerebral infarction have significant rules in time and space.