脑出血大鼠模型血清内毒素和肿瘤坏死因子-α、白细胞介素-1β表达与多器官功能障碍综合征的关系探讨

Relationship Between Serum Endotoxin,Gene Expression of TNF-α,IL-1β and Multiple Organ Dysfunction Syndrome in Cerebral Hemorrhage in Rats

目的：探讨急性脑出血致多器官功能障碍综合征（MODS）大鼠模型血清内毒素和肿瘤坏死因子（TNF）-α、白细胞介素（IL）-1β的基因表达变化规律。方法：将54只Wistar大鼠按随机化原则分为9组：正常对照组6只；假手术组6只；脑出血组42只，分为4、8、12、24、36、48和72小时时相点的7个亚组，每亚组6只。尾状核内注射Ⅶ型胶原酶0．8U建立脑出血致MODS模型。采用偶氮显色法鲎试验定量测定血清内毒素含量，采用原位杂交技术测定肺脏、肝脏、小肠和肾脏组织TNF-αmRNA、IL-1βmRNA水平；使用CMIA真彩色医学图像分析系统，检测TNF-αmRNA、、IL-1βmRNA的相对含量。结果：脑出血组血清内毒素含量较正常对照组、假手术组明显升高（P〈0．01，P〈0．0（31），于术后8小时开始升高，24～36小时达高峰，72小时仍维持较高水平。脑出血组肺脏、肝脏、小肠和肾脏组织TNF-αmRNA、IL-1βmRNA的表达自8小时开始升高，24～36小时迭高峰，12～48小时各器官组织与正常组和假手术组比较，差异均有统计学意义（P〈0．01）；肺脏、肝脏、小肠和肾脏组织中TNF-αmRNA、IL-1βmRNA的表达与血清内毒素均存在显著相关性。结论：脑出血致MODS大鼠模型存在内毒素血症，TNF-αmRNA、IL-1βmRNA的异常表达与血清内毒素显著相关，提示内毒素血症刺激炎症因子TNF-α、IL-1β的异常释放，诱发全身炎症反应，导致MODS的发生。

Objective：To explore the relationship between serum endotoxin and gene expression of TNF-α, IL-1β in cerebral hemorrhage in rats complicated by muhiple organ dysfunction syndrome and to investigate the pathogenesis of MODS. Methods： Fifty-four Wistar rats were randomly divided into nine groups：the normal control group（ n = 6）, the sham-operative group（ n = 6） , and the model group with 0.8 U Collagenase cerebral（ n = 42）. Serum endotoxin was measured with linilus lysate test. Gene expression of TNF-α, IL-1β were assayed using in situ hybridization. The area density and the optical density of positive staining expressing TNF-αmRNA,IL-1βmRNA were analyzed for the relative content using in situ hybridization and the CMIA medical imaing analysis system. Results： The content of serum endotoxin of the model group was obviously higher than that of the control group （P 〈0. O1 ,P 〈0. 001 ）. There was endotoxemia administration after acute cerebral hemorrhage. It started to increase at 8 hours after hemorrhage and peaked at 24-36 hours, and still maintained a high level at 72 hours. Expression of TNF-αmRNA, IL-1βmRNA in lung,liver,intestines and kidney tissues started to increase at 8 hours in the model groups and reached a peak at 24-36 hours. Compared with that of the normal control and sham-operative groups, expression of TNF-αmRNA, IL-1βmRNA were significantly higher at 12-48 hours in the model groups（ P 〈 0.01 ）. Relative analysis indicated that there was significant positive correlation between the TNF-αmRNA, IL-1βmRNA expression in lung, liver, kidney, intestine and plasma endotoxin level. Conclusion： Endotoxemia occurs after cerebral hemorrhage in rats complicated by MODS. The levels of gene expression of TNF-α are correlated with endotoxin levels,which implies that endotoxemia irritates the release of the inflammatory factor, and systemic inflammatory response syndrome（SIRS） is developed. This is the key process in generation of CMODS.