观察卡巴胆碱对内毒素血症小鼠肠道屏障功能的保护作用及机制。

将C57BL/6小鼠随机分为对照组、内毒素血症组、卡巴胆碱组、α银环蛇毒素组，每组10只。腹腔注射10 mg/kg内毒素建立内毒素血症模型。模型制备后15 min腹腔注射卡巴胆碱0.1 mg/kg或0.9%氯化钠溶液，内毒素注射后3 h处死动物。取距回盲瓣10 cm处回肠组织，光镜下观察回肠组织病理学改变，测定肠道组织通透性，检测紧密连接蛋白（Claudin-2）、肌球蛋白轻链激酶（MLCK）定位及蛋白含量等。

FITC-葡聚糖水平：对照组、内毒素血症组、卡巴胆碱组、α银环蛇毒素组分别为（2.33±0.51）μg/ml、（55.25±5.41）μg/ml、（19.27±3.53）μg/ml、（48.45±9.50）μg/ml，4组总体差异有统计学意义（F=111.8，P<0.05），其中内毒素血症组与对照组、内毒素血症组与卡巴胆碱组、α银环蛇毒素组与卡巴胆碱组比较，差异均有统计学意义（t分别为22.52、15.31、12.42，P均<0.05）。Claudin-2蛋白含量：对照组、内毒素血症组、卡巴胆碱组、α银环蛇毒素组分别为（0.82±0.08）μg/ml、（0.52±0.09）μg/ml、（0.77±0.05）μg/ml、（0.53±0.09）μg/ml，4组总体差异有统计学意义（F=11.61，P<0.05），其中内毒素血症组与对照组、内毒素血症组与卡巴胆碱组、α银环蛇毒素组与卡巴胆碱组比较，差异均有统计学意义（t分别为6.518、5.366、5.167，P均<0.05）。MLCK蛋白含量：对照组、内毒素血症组、卡巴胆碱组、α银环蛇毒素组分别为（0.58±0.07）μg/ml、（1.07±0.17）μg/ml、（0.69±0.11）μg/ml、（0.94±0.05）μg/ml，4组总体差异有统计学意义（F=12.64，P<0.05），其中内毒素血症组与对照组、内毒素血症组与卡巴胆碱组、α银环蛇毒素组与卡巴胆碱组比较，差异均有统计学意义（t分别为7.79、5.881、3.892，P均<0.05）。

卡巴胆碱对内毒素血症小鼠肠道屏障功能有保护作用，可降低肠道通透性，其机制可能与激活胆碱能抗炎通路有关。

To investigate the effects of carbachol on lipopolysaccharide (LPS)-induced intestinal barrier breakdown.

C57BL/6 mice were randomly divided into four groups (n=10 per group): control group, lipopolysaccharide group, carbachol group, and α-bungarotoxin group. Endotoxemia was induced by administering 10 mg/kg lipopolysaccharide via intraperitoneal injection. The mice were intraperitoneally treated with 0.1 mg/kg carbachol 15 min after LPS administration. Mice were sacrificed at 3 h after LPS administration for biochemical studies and histological examination. The localization and expression of Claudin-2 and myosin light chain kinase (MLCK), and pathologic changes of the ileum were examined.

The levels of FITC-glucan in the control group, endotoxemia group, carbachol group, and α bungarotoxin group were (2.33±0.51) μg/ml, (55.25±5.41) μg/ml, (19.27±3.53) μg/ml, and (48.45 ±9.50) μg, respectively; there was a significant difference among the four groups (F=111.8, P<0.05), as well as between the endotoxemia group and control group, between the endotoxemia group and carbachol group, and between the α bungarotoxin group and carbachol group (t=22.52, 15.31, and 12.42, P<0.05). The contents of Claudin-2 protein in the control group, endotoxemia group, carbachol group, and α bungarotoxin group were (0.82±0.08) μg/ml, (0.52±0.09) μg/ml, (0.77±0.05) μg/ml, and (0.53±0.09) μg, respectively; there was a significant difference among the four groups (F=11.61, P<0.05), as well as between the endotoxemia group and control group, between the endotoxemia group and carbachol group, and between the α bungarotoxin group and carbachol group (t=6.518, 5.366, and 5.167, respectively, P<0.05). The contents of MLCK protein in the control group, endotoxemia group, carbachol group, and α bungarotoxin group were (0.58±0.07) μg/ml, (1.07±0.17) μg/ml, (0.69±0.11) μg/ml, and (0.94 ±0.05) μg, respectively; there was a significant difference among the four groups (F=12.64, P<0.05), as well as between the endotoxemia group and control group, between the endotoxemia group and carbachol group, and between the α bungarotoxin group and carbachol group (t=7.79, 5.881, and 3.892, respectively, P<0.05).

Carbachol treatment can protect against LPS-induced intestinal barrier dysfunction and the protective effects are associated with the activation of the cholinergic anti-inflammatory pathway.