不同急性应激反应大鼠模型的比较

Comparison of different rat models of acute stress Yesponse

目的比较三种急性应激反应动物模型应激相关指标的变化,探讨建立相对适宜的急性应激反应模型。方法健康成年雄性SD大鼠40只,随机数字表法分为正常组(Ⅰ)、断尾组(Ⅱ)、烧伤组(Ⅲ)和截肢组(Ⅳ),每组10只。正常组不做处理,断尾组在靠近尾端的尾干处(即S3和S4脊髓神经之间)横切,烧伤组制成30%体表面积III度烫伤模型,截肢组以左下肢截肢作为严重创伤应激。应用酶联免疫法检测各组大鼠血清促肾上腺皮质激素(adrenocorticotropic hormone,ACTH)和皮质醇(corticosterone,CORT)的含量,免疫组织化学方法检测下丘脑c-fos蛋白的表达水平。结果与I组相比,Ⅱ、Ⅲ、Ⅳ组ACTH、CORT水平均升高(P<0.05),c-fos蛋白表达明显增加(P<0.05)。与Ⅲ组相比,Ⅱ、Ⅳ组ACTH、CORT水平、c-fos蛋白表达较高(P<0.05);但II组与IV组各项指标相比差异无统计学意义(P>0.05)。结论通过低位尾干切断制作急性应激反应模型,具有操作步骤简单、致伤程度较一致、应激效果明显等特点,能够较客观地反映人类遭遇突发事故时的应激反应,是较为理想的急性应激反应的建模方式。

Objective To compare three rat models of acute stress response and to explore an ideal experimental rat model for research of acute stress response. Methods A total of 40 clean grade male SD rats were randomly （ by random number） divided into 4 groups （ n = 10 each） ： Normal group （ group Ⅰ） , caudal trunk transection group （ group Ⅱ）, burn group （group Ⅲ）, and amputation group （group IV）. The group Ⅰ received no special treatment, the group Ⅱ received inferior caudal trunk transection at the level between sacral spinal nerve 3 and 4 （ S3, S4） , the group Ⅲ was inflicted with 30% total body surface area （TBSA） grade 3 burn on the back, and the group IV had an amputation of the left lower limb as severe traumatic stress. Rats in each group were killed at 30 minutes after treatment and blood samples were collected for measuring serum adrenocorticotropic hormone （ACTH） and corticosterone （CORT） levels by ELISA. The c-los protein expression in hypothalamic tissue was examined by immunohistochemistry. Results Compared with the group I, serum ACTH and CORT levels, and hypothalamic expression of c-fos protein in the group Ⅱ, Ⅲ, IV were significantly increased （ P 〈 0. 05 ）. Compared with the group Ⅲ, serum ACTH and CORT levels, and hypothalamic expression of c-fos protein were significantly higher in the group Ⅱ and IV （ P 〈 0.05 ） , while there was no significant difference between the group Ⅱ and IV （P 〉 0. 05）. Conclusions The preparation of acute stress response model inducedby inferior caudal trunk transection has simple operation steps and produces a traumatic injury to a similar degree, and quite well reflects the acute stress response in humans caused by sudden accident. Therefore it is a quite good method to establish acute stress response and deserves further investigation.