超声介导上调Smad7表达对腹膜炎大鼠腹膜炎症和功能的影响

目的 通过基因转染的方法上调Smad7在大鼠腹膜组织的表达，旨在探讨Smad7的高表达对大鼠腹膜炎模型的炎症反应和腹膜功能的影响。方法 Ⅱ级雄性SD大鼠18只随机分入正常组、对照组和模型组，后两组分别给予空载体和Smad7质粒转染，72 h后腹腔内注射大肠杆菌(E.Coli, ATCC 25922) 10⁹ CFU/kg体重诱导腹膜炎，在48 h后做腹膜功能试验并杀检大鼠。检测腹水及血白细胞计数、腹水细菌菌落计数。间接免疫荧光检测Smad7和CD45在腹膜组织的表达。Western印迹检测腹膜组织Smad7蛋白的表达。应用SPSS 11.0统计软件对腹膜功能与腹水白细胞数和细菌菌落数进行Pearson多元线性相关分析。 结果 与空载体组比较，Smad7转基因组大鼠腹膜组织Smad7的表达、腹水白细胞计数和腹膜组织浸润的白细胞数均显著增加，但腹水细菌菌落计数显著降低、腹膜功能显著恶化。相关分析显示腹膜功能的恶化与腹水白细胞计数相关而与腹水细菌菌落计数无相关。结论 Smad7在大鼠腹膜组织的高表达增强了腹膜局部的炎症反应，而过强的炎症反应导致腹膜功能进一步受损。

Effects of ultrasound mediated-overexpression of Smad7 on rat inflammatory peritoneum and peritoneal functions

Objective To explore the effect of overexpression of Smad7 on the peritonitis and peritoneal function. Methods Smad7 was upregulated in rat peritoneum by using ultrasound-microbubble system, and acute peritonitis was induced by intraperitoneal injection of E. Coli. Eighteen male SD rats were randomly divided into 3 groups: normal group, control group and model group. Three days after the transfection of empty plasmid or Smad7, acute peritonitis was induced by intraperitoneal injection of E.Coli ATCC 25922 109 CFU/kg. Rats were sacrificed at day 2 (5 days after the transfection). WBC counting of the blood and peritoneal fluid, peritoneal pathological change and peritoneal function (PET) were measured. The expression of Smad7 was determined by Western blot and immunostaining respectively. The infiltration of inflammatory cells was determined by immunostaining of CD45. The bacterial clone forming unit (CFU) of peritoneal fluid was also detected. The relationships between peritoneal function and WBC or bacteria in peritoneal fluid were studied by SPSS 11.0. Results Smad7 overexpressed group had an increased WBC in the the peritoneal fluid and peritoneum with significant ultrafiltration failure and increased solute transport rate over peritoneum (glucose and total protein). Bacteria CFU in peritoneal fluid decreased significantly. Further analysis showed that peritoneal function was negatively correlated to the WBC counting of peritoneal fluid, without correlation to the amount of bacteria in the peritoneal cavity. Conclusion Overexpression of Smad7 in rat peritoneal membrane enhances peritoneal local inflammatory reaction, which helps to eliminate bacteria and hampers peritoneal function.