天然蒙脱石防治烧伤后肠道细菌移位的实验研究

目的　探讨天然蒙脱石对烧伤大鼠肠道细菌移位的防治作用。　方法　SD大鼠54只,分为正常对照组6只、烧伤对照组与烧伤治疗组各24只。后两组大鼠预先喂服转染了质粒pUC19的示踪菌JM109,证实质粒已定植于其肠道后,制成30%TBSAⅢ度烫伤(以下称烧伤)模型。烧伤治疗组大鼠伤后立即喂服天然蒙脱石0. 6g d-1 kg-1,烧伤对照组大鼠不喂服药物。观察正常对照组大鼠以及烧伤对照组、烧伤治疗组大鼠伤后12h和1、3、5d血液、肠系膜淋巴结细菌移位情况,并行酶切鉴定;检测大鼠肠组织丙二醛(MDA)及超氧化物歧化酶(SOD)的含量;用病理学方法观察整段小肠的损伤情况,测量空肠黏膜绒毛高度并计算基底膜细胞核分裂相。　结果　血液细菌培养:伤后1、5d,烧伤对照组阳性鼠数多于正常对照组,烧伤治疗组阳性鼠数少于烧伤对照组(P<0 05).肠系膜淋巴结细菌定量:烧伤治疗组伤后1、5d为(38±16)、(68±20)集落形成单位(CFU) /g;烧伤对照组伤后1、5d为( 228±67 )、( 183±29 )CFU/g,明显高于前者(P<0. 01 ).MDA、SOD含量:烧伤治疗组与烧伤对照组伤后各时相点比较,差异有统计学意义(P<0. 05).烧伤治疗组大鼠伤后各时相点空肠绒毛高度及基底膜细胞核分裂相明显高于或多于烧伤对照组(P<0. 05或0. 01)。　结论　天然蒙脱石对严重烧伤大鼠肠

An experimental study on the prevention of enteral bacterial translocation in scalded rats by smectite powder

OBJECTIVE: To explore the preventive and treatment effects of smectite powder on enteral bacterial translocation in scalded rats. METHODS: Fifty-four Sprague-Dawley (SD) rats were randomly divided into three groups, i.e. normal control (A, n = 6), burn control (B, n = 24), and burn treatment (T, n = 24) groups. The rats in B and T groups were fed with tracing bacteria JM109, which was transfected with PUC19 plasmid in advance. The rats were subjected to 30% TBSA scald injury after the plasmid was shown to have colonized in the intestine. Smectite powder (0.6 g/day/kg) was fed to rats of T group immediately after the scalding, while those in B group received no smectite powder. Bacterial translocation in blood and mesenteric lymph nodes in all groups was observed and identified by enzyme digestion at 12 post scald hour (PSH) and on 1, 3 and 5 post-scald days (PSD). The contents of malondialdehyde (MDA) and superoxide dismutase (SOD) were determined in rat intestinal tissue. And the degree of injury to the entire small intestine was observed pathologically. The villus height of intestinal mucosa was measured, and the rate of epithelial nuclear splitting of mucosal crypts was calculated. RESULTS: The number of rats with positive blood bacterial culture in B group was obviously higher than that in A and T groups (P < 0.05) on 1 and 5 PSD. The bacterial quantity in mesenteric lymph nodes (MLN) in T group on 1 PSD (38 +/- 16 CFU/g) and 5 PSD (68 +/- 20 CFU/g) were obviously lower than those in B group (228 +/- 67 vs 183 +/- 29 CFU/g, P < 0.05). There was significant difference in the intestinal contents of MDA and SOD between B and T groups at each time point (P < 0.05). The rat jejunum villus height and the epithelial nuclear splitting in the small intestine mucosa in T group were evidently higher than those in B group (P < 0.05 or 0.01). CONCLUSION: Smectite powder is beneficial to the protection of the intestinal mucosa in scalded rats, and can effectively prevent postburn intestinal bacterial translocation in rats.