缺氧大鼠脑组织中的15-脂加氧酶表达与定位研究

Expression and location of 15-lipoxygenase in hypoxic rat brain

目的:通过对15-脂加氧酶(15-lipoxygenase,15-LO)在缺氧大鼠脑组织中的表达及定位研究,明确15-羟廿碳四烯酸(15-hydroxyeicosatetrae-noicacid,15-HETE与脑缺氧的关系,进一步探讨缺氧引起中枢神经系)统功能障碍的机制。方法:实验于2002-01/12在哈尔滨医科大学药理学教学基地与病理学实验室完成。将12只Wistar大鼠随机分为两组:对照组,吸大气FiO2为210mL/L;缺氧组,即将大鼠置于缺氧箱中,吸入氮气与氧气的混合气体(90∶10),即FiO为100mL/L。9d后将动物麻醉后断头取脑,制成2冷冻切片,进行免疫组化与原位杂交实验。结果:正常组,15-LOmRNA、蛋白质在脑内有少量表达。缺氧条件下,二者表达均增加(P<0.01)。15-LOmRNA定位于血管内皮细胞、平滑肌细胞、海马、脉络膜及神经元的胞核内,胞浆亦有少量。此外神经胶质细胞内也有少量表达。15-LO蛋白质阳性染色主要存在于血管内皮细胞、平滑肌细胞的胞浆内,海马、神经元内未见表达。此外,神经胶质细胞、脉络膜亦有少量表达。结论:缺氧条件下脑组织15-LO表达增加,参与了脑缺氧后的损伤过程。

AIM:To confirm the relation between 15 hydroxyeicosatetraenoic acid(15 HETE) and cerebral hypoxia through studying the expressions and location of 15 lipox ygenase(15 OL) in hypoxic rat brain for further inverstigating the mechanism of hypoxia induced dysfunction of central nervous system. METHODS:The study was finished in the Educational Base and Pathological Labora tory Department of Harbin Medical University between January and December 2002.T welve Wistar rats were randomly divided into two groups:control group raised in normal environment(FiO2,210 mL/L) and hypoxic group raised in hypoxic box contai ning mixed gas of nitrogen gas and oxygen(90∶10,100 mL/L).After 9 days, the rat s were killed under anesthesia and the brains were taken out and sliced into fro zen sections.Then in situ hybridization and immunohistochemistry staining were p erformed. RESULTS:There were little positive cells expressing 15 LO mRNA and protein in the control group, but positive cells which expressed 15 LO mRNA and protein i n the hypoxic group were significantly increased(P< 0.01).15 LO mRNA was mainly expressed in hippocampus,vascular endothelial cells,smooth muscle cells,choroid and neuronal nuclei,and little in cytoplasm and neuroglial cells.While 15 LO p rotein was mainly found in the cytoplasm of endothelial cells and smooth muscle cells,hippocampus,little in choroids and neuroglial cells, but not in neurons. CONCLUSION:Hypoxia can improve the expression of 15 LO in brain that