大鼠脑缺血-再灌注后下丘脑室旁核促肾上腺皮质激素的表达

目的 探讨大鼠脑缺血-再灌注后，不同时期中枢下丘脑室旁核促肾上腺皮质激素样阳性免疫物的表达。方法 取雄性Wislar大鼠70只，随机分成对照组（10只）、假手术对照组（30只）及脑缺血-再灌注组（30只）以颈动脉引流法行全脑缺血-再灌注造模，术后分6、24、72h3个时间段取脑，釆用免疫细胞化学技术，用图像分析系统行下丘脑室旁核促肾上腺皮质激素样阳性免疫反应面积、平均吸光度值检测。结果 显微镜下观察示，促肾上腺皮质激素样阳性免疫物呈深棕色，胞核深染，并广泛分布于中枢各脑区，核仁清晰可辨、在丘脑及下丘脑区域有散在分布“串珠”状阳性纤维。图像分析结果显示，假手术对照组、脑缺血-再灌注组大鼠的阳性免疫面积和平均吸光度值呈同步变化：从术后6h开始，假手术对照组、脑缺血-再灌注组大鼠均较正常对照组显着升高，术后24h达高峰（P〈0．05），然后逐渐回落。在3个不同时间段，3组间差异均有显着意义（P〈0．05），术后6及24h为：脑缺血-再灌注组，假手术对照组，正常对照组；术后72h为：假手术对照组〉正常对照组〉脑缺血-再灌注组。结论 在脑缺血-再灌注不同时间段，下丘脑室旁核神经元促肾上腺皮质激素样阳性免疫物表达呈现明显的时间规律；促肾上腺皮质激素可能在神经元功能调控，中枢内环境控制及脑缺血-再灌注损伤过程中发挥着重要作用。

Alterations in protein expression of ACTH after ischemia-reperfusion in the hypothalamic paraventricular nucleus of rat brain

Objective To investigate the changes in protein expression of ACTH levels in the hypothalamic paraventricular nucleus of rat brain after ischemia-reperfusion. Methods 70 male wistar rats were randomly assigned into 3 groups: normal control group (n=10),sham-ischemia group(n=30), cerebral ischemia-reperfusion group(n=30). Temporary cerebral ischemia-reperfusion model was established by common carotid artery blood drainage method. Brain section was obtained by cryostat sectioning. The section was prepared for ACTH immunohistochemistry staining and was observed by optical microscope. Quantitate analysis was carried out for ACTH immunoreactive matter stain area and density. Results Under optical microscope, ACTH positive substrate appeared dark brown, dark stained cell nuclear scattered widely in each brain area with clear nucleolus. There were linked-beads-like neuron fibers in thalamus and hypothalamus. The imaging analysis showed that positive substrate stain area and density changed synchronously in the sham operation group and cerebral ischemia-reperfusion group. Both stain area and density in these two groups got more than that in normal group 6 h after the operation and kept going until 24 h after that(P<0.05), then declined gradually. At all three different time points, the difference of stain area and density among the three groups were significant(P<0.05). Conclusion The presen t results demonstrate that the expression of ACTH protein in paraventricular hypothalamic nucleus atearlyreperfusion might play an important role in the mechanism for delayed brain ischemia reperfusion injury.