Hemeoxgenase-1 mediates the protective effect of hyperbaric oxygen preconditioning against the brain edema after experimental hemorrhage in rats / 中华急诊医学杂志

ABSTRACT

Objective To investigate the role of Heme oxygenase-1 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 preconditioning,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)HBOP +ZnPP group,in which rats had a micro-pump intra-peritoneally implanted containing a specific HO-1 inhibitor ZnPPⅨ (Zinc protoporphyrin IX,0.01 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-conditioning,rats received an infusion of 100 μL autologous blood into the caudate nucleus to form a simulated intracerebrum 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-conditioning + 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.