title: Effect of hyperbaric oxygen preconditioning on peri-hemorrhagic focal edema and aquaporin-4 expression.
abstract: The aim of the present study was to investigate the effect of hyperbaric oxygen preconditioning (HBO-PC) on peri-hemorrhagic focal edema and aquaporin-4 (AQP-4) expression in an experimental intracerebral hemorrhage (ICH) rat model. Sixty-six Sprague Dawley® rats were divided into three groups: The sham-surgery group (SHG; n=6); the control group (A-ICH; n=30), in which the rats were injected with autologous blood; and the experimental HBO-PC group (P-HBO; n=30). The rats underwent brain edema and AQP-4 detection at 5 postoperative time-points (24, 48 and 72 h and 5 and 7 days). The water content in the brain tissues of the A-ICH animals was higher than that in the brain tissues of the SHG rats at each time-point (P<0.05), and the edema in the P-HBO was significantly more severe 24 and 48 h postoperatively than that at 7 days postoperatively (P<0.05). The difference between the P-HBO and A-ICH was significant at 48 and 72 h postoperatively (P<0.05). AQP-4 was expressed in the post-hemorrhagic rat brains of all groups; the SHG animals exhibited low expression, while the A-ICH animals exhibited an increased expression 24 h postoperatively. In the A-ICH, expression peaked at 48 h postoperatively and began to decrease gradually after 72 h. At the 7-day time-point, the expression level in the A-ICH was closer to but still higher than that of the SHG animals (P<0.05). The differences between the P-HBO and A-ICH animals at the postoperative 24-h, 48-h and 7-day time-points were statistically significant (P<0.05). In conclusion, HBO-PC may downregulate AQP-4 expression to reduce the intracerebral edema, thus strengthening tolerance to ICH and protecting the nerves.
authors.affiliation: Department of Rehabilitation, The People's Hospital of Zhangdian, Zibo, Shandong 255025, P.R. China.
authors.forename: Jinyong
authors.initials: J
authors.lastname: Fang
authors.affiliation: Department of Rehabilitation, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei 050000, P.R. China.
authors.forename: Hongling
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Neurological Intervention, The Second Hospital of Qinhuangdao, Qinhuangdao, Hebei 066600, P.R. China.
authors.forename: Guanglei
authors.initials: G
authors.lastname: Li
authors.affiliation: Department of Rehabilitation, Cangzhou Hospital of Integrated Traditional Chinese and Western Medicine, Cangzhou, Hebei 061001, P.R. China.
authors.forename: Lichun
authors.initials: L
authors.lastname: Wang
keywords: aquaporin; hyperbaric oxygen preconditioning; intracerebral edema; intracerebral hemorrhage; rats