大肠杆菌内毒素诱导的大鼠眼内炎表现及细胞因子的表达

目的 观察大肠杆菌内毒素(LPS)诱导的大鼠眼内炎模型组织病理学特征和玻璃体内肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)和LPS的表达模式.方法 采用随机数字表法将大鼠随机分为生理盐水对照组(SC组)136只、眼内炎组(EO组)168只、空白对照组(BC组)12只.E0组玻璃体腔注射5 μl LPS溶液诱导眼内炎动物模型;SC组注入等量无菌生理盐水;BC组不作任何干预.注射后6、12、24、48、72 h,5、7 d,观察大鼠眼部炎症表现并分别摘除各组眼球行组织病理学检查,并取其玻璃体检测细胞因子TNF-α、IL-1β和LPS的浓度.结果 EO组注射后6～72 h,眼内可见严重炎症反应,注射后7 d炎症基本消退.注射后24 h,眼内白细胞浸润数量为(1224.64±132.2)个/眼,达到高峰;注射后72 h,浸润细胞数量迅速下降至(342.25±47.7)个/眼.EO组注射后24 h,TNF-α和IL-1β浓度分别为(996.18±89.45)、(5556±1440)pg/ml,均达到高峰并持续至注射后48 h,随后迅速下降;注射后7 d,TNF-α和IL-1β浓度分别为(22.16±5.84)、(73.7±18.7)pg/ml.EO组注射后72 h,玻璃体腔内LPS含量迅速下降为(11.03±3.41)ng,7 d后玻璃体腔内LPS含量为(0.22±0.08)ng.结论 大鼠眼内炎模型的主要病理特征是大量白细胞眼内浸润,TNF-α、IL-1β的高水平表达以及玻璃体腔自发性细菌成分清除;TNF-α、IL-1β表达模式与LPS眼内清除过程一致.

Escheriehia coil lipopolysaeeharide-induced endophthalmitis and cytokine expression

Objective To observe the histopathologic features and expression patterns of tumor necrosis factor-α (TNF-α), interleukin-1β(IL-1β) and Escherichia coli lipopolysaccharide (LPS) in the rat vitreous with LPS induced-endophthalmitis. Methods Wistar rats were randomly divided into saline control group (SC, 136 rats),endophthalmitis group (EO, 168 rats)and blank control group (BC, 12 rats). EO group received an intravitreal injection of 5βl LPS; SC group received 5μl sterile saline and no intervention for BC group. Six, 12, 24, 48, and 72 hours, 5 and 7 days after injection, intraocular inflammation were observed and the eyes and vitreous were collected for histopathological examination and measurement of TNF-α, IL-1β and LPS expression. Results Severe inflammatory responses in the eyes were observed in EO group between six and 72 hours after LPS injection, ocular inflammation subsided seven days after LPS injection. In the vitreous, a peak neutrophil count was observed at 24 hours (1224. 64±132.2) cells/eye that rapidly declined at 72 hours (342. 25± 47. 7) cells/eye. The levels of TNF-α and IL-1β in EO group were peaked at 24 hours with (996.18±89.45) and(5556±1440) pg/L, respectively;Persisted at 48 hours and began to decline rapidly thereafter. Seven days after LPS injection, levels of TNF-α and IL-1β returned to baseline with (22.16 ±5.84) and (73.7±18. 7) pg/L, respectively. LPS concentration in EO group decrease rapidly at 72 hours with (11.03±3.41) ng and disappear on days 7 with (0.22±0.08) ng after LPS injection. Conclusions Massive neutrophils infiltration, high levels expression of TNF-α and IL-1β and spontaneous elimination of bacterial elements in vitreous cavity were major pathologic characteristics in this experimental model. The expression patterns of TNF-α, IL-1β were in accord with LPS clearance process.