Beasley T C, Bari F, Thore C, Thrikawala N, Louis T, Busija D
Department of Neurobiology and Anatomy, Bowman Gray School of Medicine Wake Forest University, Winston-Salem, NC 27157-1083, USA.
Brain Res Dev Brain Res. 1998 Jan 14;105(1):125-35.
Indomethacin-sensitive mechanisms involved in inducible heat shock protein 70 (iHSP 70) synthesis were investigated at 6 h after global cerebral ischemia in parietal cortex and hippocampus. In anesthetized piglets, increased intracranial pressure was used to produce 5 or 10 min of cerebral ischemia. Brain regions were sampled for immunoblot analysis, immunohistochemistry and morphology. Immunoblots revealed differential expression of iHSP 70 in untreated brains. Cerebellum contained substantial amounts of iHSP 70 while lower levels were present in parietal cortex and hippocampus. Detectable increases in iHSP 70 were observed at 2 h after ischemia in parietal cortex and hippocampus. Using immunoblot data, calculation of percent change from control at 6 h after ischemia revealed significant (p < 0.05) increases in iHSP 70 of 111 +/- 39% (x +/- sem) (n = 6) in parietal cortex and 195 +/- 69% (n = 8) in hippocampus. Increased iHSP 70 immunoreactivity occurred primarily in the granular/subgranular area of the dentate gyrus 6 h after ischemia. Histological staining revealed little cellular injury at 6 h after ischemia in the granular/subgranular region injury whereas the CA3 region, which lacked iHSP 70 staining, displayed modest cellular injury. Cellular injury was also observed in cortical layers II/III and VI. At 6 h after ischemia, indomethacin pretreatment (5 mg/kg, i.v.) attenuated the iHSP 70 increases in parietal cortex and hippocampus (7 +/- 30% and 89 +/- 30%, respectively n = 5; p < 0.05 compared to ischemia). Also, the increase in iHSP 70 immunoreactivity and appearance of cellular injury were not detected with indomethacin pretreatment. Thus, prior administration of indomethacin is associated with attenuation of ischemia-induced increases in iHSP 70 and cellular injury.
在全脑缺血6小时后，研究了顶叶皮质和海马中参与诱导型热休克蛋白70（iHSP 70）合成的吲哚美辛敏感机制。在麻醉的仔猪中，通过升高颅内压来产生5或10分钟的脑缺血。采集脑区样本进行免疫印迹分析、免疫组织化学和形态学研究。免疫印迹显示，在未处理的大脑中iHSP 70存在差异表达。小脑中含有大量的iHSP 70，而顶叶皮质和海马中的水平较低。在缺血后2小时，在顶叶皮质和海马中观察到iHSP 70有可检测到的增加。利用免疫印迹数据，计算缺血后6小时相对于对照的变化百分比，结果显示顶叶皮质中iHSP 70显著（p < 0.05）增加111±39%（x±sem）（n = 6），海马中增加195±69%（n = 8）。缺血后6小时，iHSP 70免疫反应性增加主要发生在齿状回的颗粒/亚颗粒区。组织学染色显示，缺血后6小时，颗粒/亚颗粒区几乎没有细胞损伤，而缺乏iHSP 70染色的CA3区则有适度的细胞损伤。在皮质II/III层和VI层也观察到细胞损伤。缺血后6小时，吲哚美辛预处理（5mg/kg，静脉注射）减弱了顶叶皮质和海马中iHSP 70的增加（分别为7±30%和89±30%，n = 5；与缺血组相比，p < 0.05）。此外，吲哚美辛预处理未检测到iHSP 70免疫反应性增加和细胞损伤的出现。因此，预先给予吲哚美辛与减弱缺血诱导的iHSP 70增加和细胞损伤有关。
