间断注射小剂量脂多糖建立大鼠的慢性炎症模型

目的探讨小剂量脂多糖(LPS)间断注射建立大鼠慢性炎症模型的可行性。方法将40只SD大鼠随机均分为对照组与LPS处理1、2、3、4周组。除对照组外的各组大鼠尾静脉注射LPS(0.2 mg·kg-1·w-1),对照组注射等体积生理盐水。观察各组大鼠存活情况,检测血白细胞计数与分类、血清白细胞介素6(IL-6)、肿瘤坏死因子α(TNF-α)、超敏C反应蛋白(hs-CRP),以及心、肝、肺、肾HE染色镜检。结果大鼠全部存活。尾静脉注射LPS后大鼠血白细胞总数、中性粒细胞比例及血清IL-6、TNF-α、hs-CRP水平均增高,淋巴细胞比例降低,心、肝、肺、肾出现以炎性细胞浸润、组织淤血水肿为主的病理变化。结论 SD大鼠小剂量间断尾静脉注射LPS可诱导典型慢性炎症,可供LPS相关慢性炎症的长期研究之用。

Establishing a chronic inflammation model in rats by low dose intermittent injection of lipopolysaccharide

OBJECTIVE To establish a rat model with chronic inflammation induced by intermittent injection of lipopolysaccharide(LPS) at a low dose.METHODS 40 SD rats were randomly divided into control group and LPS-treated 1,2,3,4 week group.Rats in LPS-treated groups received by intermittent injection through LPS(0.2 mg·kg-1·w-1) by intermittent injection through caudal vein injection once a week.Rats in control group received isometric stroke-physiological saline solution injection in the same way.The survival condition of each group was recorded.The peripheral white blood cell count and classification were measured.The levels of serum interleukin-6(IL-6),tumor necrosis factor alpha(TNF-α) and high-sensitivity C-reactive protein(hs-CRP) were detected by enzyme-linked immunosorbent assay(ELISA).Regular HE staining was applied to evaluate the inflammatory reaction in heart,liver,lung and kidney tissue.RESULTS The animals were all survived up to the endpoint of experiment.Not only the peripheral white blood cell count and the neutrophils ratio,but also the level of rat serum IL-6,TNF-α and hs-CRP were raised after injection of LPS.However,the lymphocytes ratio was decreased after low dose LPS injection.The tissue injury due to inflammatory cells infiltrating and blood stasis plus hydroncus,as primary pathological manifestations,was observed after LPS treating.CONCLUSION The SD rat model with classic chronic inflammation can be successfully established by intermittent injection of LPS through caudal vein at a low dose.It may be used for the long term study of the LPS-related chronic inflammation.