Objective To investigate the effects of splenectomy on severe thermal trauma-induced intestinal barrier breakdown in rats. Methods Eighty Wistar rats were randomly divided into four groups equally as control,burn,burn + splenectomy 7 days (B+ SP7) and burn + splenectomy 14 days (B+ SP14). After operation 7 days and 14 days,the serum endotoxin levels,nuclear factor-vB (NF-κB) and tumor necrosis factor-α (TNF-α) were assayed. Small segments of terminal ileum mucosa were taken for the determination of morphological analysis with image analysis system,and the expression of tight junction protein-1 (ZO1) and occludin were analyzed by Western blot. Results Compared with control group,burn group significantly increased in serum endotoxin levels [d. 071 ± 0. 29 ) EU/mL,NF-κB (125 ± 14. 1) pg/mL,and TNF-α(99. 1 ± 18. 1) μg/mL],which were 301% ,247% and 608% higher than those in control group (all P<0. 01). While the values in B+ SP7 group rose 226% ,168% and 370% than those in control group (all P<0. 01). But in B + SP14 group, only serum TNF-α increased significantly (445%,P<0. 01), which was higher than in B + SP7 group (P<0. 01). Morphometricly the intestinal mucosa became obvious atrophy in burn group, the average intestinal villus height and mucosal thickness were decreased significantly (P<0. 01). After splenectomy 7 days or 14 days, the extents of average intestinal villus height and mucosal thickness were less than those in burn group (P<0. 01). The relative optical density of Western blot images were significantly decreased on ZO-1 and occludin (0. 56 ± 0. 17 vs. 1. 30 ± 0. 27,P<0. 01) in burn group quantitatively. The degrees in B + SP7 group were less than those in burn group (P<0. 01). In B + SP14 group,only occludin decreased more. Conclusions This study suggested that severe thermal injury damaged the intestinal mucosal barrier. Splenectomy may provide a therapeutic benefit in restoring burn-induced intestinal barrier by decreasing the release of inflammatory cytokines and recovering tight junction proteins.%目的 研究脾切除对重度热伤大鼠肠黏膜屏障的影响.方法 80只Wistar大鼠,随机分成对照组、热伤组(B组),热伤+脾切除7天组(B+ SP7组)和热伤+脾切除14天组(B+ SP14组).对照组置于25℃水浴；热伤组于92℃水浴造成30％ Ⅲ度烫伤；热伤+脾切除组在热伤同时行脾切除,分别于伤后7天及14天抽血后处死.检测血清内毒素、核因子κB(nuclear factor-κB,NF-κB)和肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)含量；病理图像分析仪观察末端回肠的形态学变化,并采用Western blot法检测小肠黏膜上皮紧密连接蛋白-1(zonula occludens-1,ZO-1)和闭锁蛋白(occludin)的表达.结果 B组大鼠血清内毒素[(1.071±0.29)EU/mL]、NF-κB[(125±14.1) pg/mL]和TNF-α[(99.1±18.1) μg/mL]含量较对照组分别上升301％、247％和608％ (P＜0.01),B+ SP7组较对照组分别增加226％、168％和370％,差异有统计学意义(P＜0.01).B+SP14组仅血清TNF-α较对照组上升445％,上升幅度高于7天组(P＜0.01).形态学上热伤组小肠黏膜明显萎缩,平均肠绒毛高度和黏膜厚度较对照组下降明显(P＜0.01).切除脾脏7天和14天后,平均肠绒毛高度和黏膜厚度的下降幅度小于热伤组(P＜0.01).用图像采集系统定量分析Western blot条带的相对光密度值,热伤后ZO-1 (0.56±0.17)和闭锁蛋白(1.30±0.27)均明显下降(P＜0.01)；相对于对照组,B+SP7组的下降幅度小于热伤组(均P＜0.01),B+SP14组仅闭锁蛋白的下降幅度小于B+ SP7组.结论 严重热伤损伤小肠黏膜屏障,脾切除后短期内由于其释放的细胞因子减少,无脾动物肠黏膜上皮细胞紧密连接蛋白表达恢复,肠屏障的损害减轻.
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