高压氧预处理对实验性脑出血大鼠出血灶周围水肿及水通道蛋白-4表达的影响

目的:探讨高压氧预处理(HBO-PC)对实验性脑出血大鼠血肿周围水肿及水通道蛋白-4(AQP-4)表达的影响。方法:将66只健康雄性SD大鼠随机分为3组:①假手术组(SHG)6只;②对照组(自体血注入的脑出血组,A-ICH)30只;③实验组(高压氧预处理组,HBO-PC)(即在脑出血模型制作前先进行5d高压氧治疗)30只。后两组又随机分为术后24h、48h、72h、5d、7d5个时间点组,每组6只大鼠。于相应时间点将大鼠处死,进行脑水肿和AQP-4的测定。结果:A-ICH模型的成功率为60%,A-ICH脑组织含水量各时间点均高于SHG组(P<0.05),其中术后48h水肿最明显,之后脑水肿虽有减轻趋势,但在7d时仍高于SHG组,差异有显著性意义(P<0.05)。HBO-PC组脑水肿在术后24h和48h显著,与7d组比较差异有显著性意义(P<0.05),之后水肿程度逐渐减轻,7d时基本恢复到SHG组水平。HBO-PC与A-ICH组相比,水肿程度较轻,尤其在术后48h和72h,差异显著(P<0.05)。脑出血后大鼠脑组织中AQP-4在各组中均有表达,SHG组呈低表达状态,A-ICH24h后开始升高,48h达到高峰,72h后开始逐渐降低,7d时表达水平接近SHG组,但仍高于SHG组(P<0.05)。HBO-PC组各时间点表达与A-ICH组一致,但低于A-ICH组,两组在术后24h、48h和7d差异有显著性意义(P<0.05)。结论:HBO-PC可能通过下调AQP-4的表达减轻脑水肿,从而起到增强对脑出血的耐受和神经保护作用。

Effects of hyperbaric oxygen preconditioning on brain edema and aquaporin-4 around experimental intracerebral hemorrhage lesion in rats

AbstractObjective: To study the effects of hyperbaric oxygen preconditioning(HBO-PC) on brain edema and aquaporin-4(AQP-4) around experimental intracerebral hemorrhage(ICH) lesion in rats. Method: Sixty-six male SD rats were divided randomly into three groups: sham group (SHG, 6 rats); control group (A-ICH, 30 rats) and trial group (HBO-PC, 30 rats). The rats were sacrificed at 24h, 48h, 72h, 5d, 7d post operation. Brain edema and AQP-4 were tested. Result: A-ICH autoblood injection-ICH model success ratio was 60%. Water contents in brain of A-ICH and HBO-PC groups were significant higher than that of SHG at all time points. Brain edema of HBO-PC was most remarkable at 24h and 48h post-operation(P<0.05), but was lighter than that of A-ICH especially at 48h and 72h post-operation(P<0.05). Expression of AQP-4 appeared in all groups, that of SHG group was lower than that of A-ICH and HBO-PC groups. The difference between A-ICH and HBO-PC was significant at 24h, 48h and 7d post operation(P<0.05). Conclusion: HBO-PC may enhance the tolerance of rats to ICH and protect nervous function by downregulating expression of AQP-4 and reducing brain edema.