高压氧预处理诱导血红素加氧酶-1减轻大鼠脑出血后脑水肿

Hemeoxgenase-1 mediates the protective effect of hyperbaric oxygen preconditioning against thebrain edema after experimental hemorrhage in rats

目的研究血红素加氧酶-1（hemeoxygenase-1，HO-1）在高压氧预处理（hyperbaicoxygenpreconditioning，HBOP）减轻大鼠脑出血后脑水肿形成过程中的作用。方法本实验共选用54只雄性Spradgue-Dawley大鼠，体质量300～350g，分为两部分：第1部分，6只大鼠随机（随机数字法）分为两组（n=3），分别接受高压氧预处理（HBOP组）或假预处理（假预处理组）；预处理结束24h后处死，取基底节组织，采用Westernblot法检测HO一1蛋白含量。第2部分：48只SD大鼠随机（随机数字法）分为四组（n=12），各组大鼠在预处理前腹腔内置人含HO-1抑制剂锌原卟啉Ⅸ（zincprotoporphyrinIX，ZnPPIX）的缓泵（0．01mg／kg）（HBOP＋ZnPP组、假预处理＋ZnPP组）或含2mL二甲基亚砜（dimethylsulfoxide，DMSO）载体溶剂的缓释泵作为对照（HBOP＋DMSO组、假预处理＋DMSO组），随后接受高压氧预处理（HBOP组＋ZnPP组，HBOP＋DMSO组）或假预处理（假预处理＋ZnPP组，假预处理＋DMSO组）。预处理结束24h后，立体定向基底节内注射自体股动脉血100txL建立基底节脑出血模型，72h后处死，采用干湿质量法测定脑组织水含量。统计学分析采用Stata7．0软件进行成组设计资料的￡检验。结果HBOP组大鼠基底节组织内HO-1蛋白含量与假预处理相比差异具有统计学意义（P〈0．05）；HBOP＋DMSO组大鼠血肿同侧基底节组织水含量为（81．4±0．9）％，显著低于假预处理＋DMSO组（82．6±0．8）％（P〈0．05），但大鼠接受高压氧预处理同时腹腔内给予HO-1抑制剂ZnPPIX则抵消了HBOP减轻脑出血后脑水肿的效应[（82．8±0．9）％VS．（82．6±0．7）％（P〉0．05）]。结论高压氧预处理显著减轻大鼠脑出血后脑水肿，其作用机制与其上调HO-1蛋白的表达有关。

Objective To investigate the role of Heme oxygenase-I in the effect of hyperbaric oxygen preconditioning （HBOP） against the brain edema formation after experimental intracerebral hemorrhage in rats. Methods The study was carried out by animal experiment in two steps by using 54 Spradgue-Dawley rats weighting from 300-350 g. In the first step, rats were treated with HBOP （ HBOP group, n = 3 ） or with sham pre-conditioning （Sham pre-conditioning group, n = 3）. All the rats were sacrificed 24 h after the pre- conditioning, and basal ganglion of brain tissue was taken for detect HO-1 level by using western blot analysis. In the second step, rats were divided into 4 groups （ n = 12 in each group） ： /-/BOP ＋ ZnPP group,in which rats had a micro-pump intra-peritoneally implanted containing a specific HO-1 inhibitor ZnPP1X （Zinc protoporphyrin IX, O. 01 mg./kg）, Sham pre-conditioning ＋ Znpp group, HBOP ＋ DMSO group, in which rats with a intra-peritoneal micro-pump containing 2 mL Dimethyl sulfoxide （DMSO, a solvent vehicle） and Sham pre-conditioning ＋ DMSO group before HBOP. At 24 hours after the pre-couditioning, rats received an infusion of 100 ILL autologous blood into the caudate nucleus to form a simulated intra- cerebrum hemorrhage （ ICH）, and were sacrificed 72 h later for brain water content measurements. All data were analyzed by using Stata 7.0 software and statistical analyses were carried out by two-tailed Student t test. Results Compared with the Sham pre-conditioning group, the HBOP group had significant higher level of HO-1. Compared with the Sham pre-eonditioning ＋ DMSO group, the HBOP ＋ DMSO group had a significant lower level of water content in the ipsilateral basal ganglion [ （81.4 -＋ 0. 9）% vs. （82. 6 ±0. 8） % （P 〈0. 05 ） ], however, peritoneal infusion of ZnPP IX before HBOP abolished HBOP-induced protection against brain edema formation after experimental ICH [ （82. 8±0. 9）% vs. （82. 6±0. 7）% （P 〉 0. 05 ）]. Conclusions Hyperbaric oxygen preconditioning attenuate brain edema formation after experimental ICH in rats, and this protection is attributed to the activation of HO-1.