红细胞在大鼠创伤性脑内出血后脑水肿中的作用

Role of erythrocyte on brain edema development after traumatic intracerebral hemorrhage in rats

目的研究红细胞对创伤性脑内出血(traumatic intracerebral hemorrhage,TICH)后脑水肿的影响,并探讨其作用机制。方法自由落体打击法造成大鼠脑外伤,借助鼠脑立体定向仪向伤区脑皮质内注射全血(全血)、溶解红细胞(LRBC)或压积红细胞(PRBC),造成TICH模型。于伤后1,3,5 d处死大鼠,取伤区脑组织测含水量,免疫组化SABC法检测血红素氧合酶-1(HO -1)和肿瘤坏死因子(TNF)-α的表达。结果(1)创伤性脑损伤(TBI)、全血和PRBC三组第3天的脑含水量最高,LRBC组第1天的含水量最高；四组间比较,1 d时LRBC含水量最高,3 d时PRBC和全血组含水量最高。(2)在全血、PRBC和LRBC组,HO-1和TNF-α阳性表达的强弱与脑含水量的高低变化相一致。结论在TICH中,红细胞对早期(第1天)脑水肿的形成无明显作用,而对迟发性(第3天)脑水肿的形成有重要作用,其机制涉及红细胞的降解产物和炎症反应等。

Objective To study the effects of erythrocyte on brain edema after traumatic i,tracerebral hemorrhage（TICH） and explore the mechanisms of erythrocyte in brain edema development following TICH. Methods Firstly, the brain injury model of SD rat was established by applying a free-falling device, then whole blood （WB） ,lysed RBC （LRBC） or parked RBC （PRBC） were infused with stereotaetie guidance into injured cortex to produce the model of TICH. All rats were killed at 1, 3, and 5 days after injury. The brain water content was measured, immunohistochemistry （SABC） was applied to test HO-1 and TNF-α expressions. Results 1. In WB group, PRBC group and TBI group, the brain water content was the highest on the third day. The brain water content of LRBC group was markedly higher on the first day than on the third and fifth days. Comparison among the four groups showed the water content was the highest on the 1 st day in LRBC group, and on the 3rd day in WB and PRBC groups ; there was no significant difference among the four groups on 5th day. 2. The positive expression of HO-1 and TNF-α coincided with the change of the water content in groups of WB, PRBC and LRBC. Conclusions In rat model of TICH, RBC plays an important role in delayed brain edema formation （3 days after injury）, but has no influence at early stage （ 1 day after injury）. The mechanisms of delayed brain edema involves RBC breakdown and inflammation reaction.