Protective effect of carbon monoxide releasing molecule-2 on intestinal epithelial barrier function in shock rats / 中华急诊医学杂志

ABSTRACT

Objective To investigate the protective effect of carbon monoxide release molecule-2 (CORM-2) on intestinal barrier injury in shock rats. Methods Thirty-two rats were equally and randomly divided into 4 groups the sham operated group, shock group, carbon monoxide releasing molecule-2 (CORM-2) group and inactivated CORM-2 (iCORM-2) group. A modified Wiggers model was used in inducing hemorrhagic shock. In the CORM-2 group and iCORM-2 group, the animals were intraperitoneally injected CORM-2 (5 mg/kg) or iCORM-2 (5 mg/kg) 1 h before inducing shock. The ileum tissues were harvested 24 h after operation or 24 h after inducing shock, and the histopathologic changes and ultrastructure of the ileum were observed. The expressions of ZO-1, Occludin, and Claudin3 protein in ileum intestinal mucosa were determined by Western blot. TNF-α and D-lactic acid levels in the blood were measured by enzyme-linked immunosorbent assay (ELISA). Data of multi-groups were analyzed by one way variance (ANOVA) and inter-group comparisons were made by the least significant difference (LSD)-t tests. Kruskal Wallis rank sum test was used when homogeneity of variance were not met. The value of P<0.05 was considered statistically significant. Results (1) The pathological changes and ultrastructural damage of ileum mucosa in the shock group were obvious. CORM-2 can significantly improve the pathological morphology and ultrastructural integrity of intestinal mucosa in shock rats. (2) Compared with the sham operated group, the expressions of Claudin3, Occludin, and ZO-1 of ileum intestinal mucosa were significantly decreased in the shock group and iCORM-2 group(all P<0.05), but in the CORM-2 group, only the expression of Claudin3 and ZO-1 were decreased(P<0.05). The expression of these proteins in the CORM-2 group was higher than that in the shock group and iCORM-2 group. (3) Compared with the sham operated group, the levels of D-lactic acid and TNF-α in the shock group and iCORM-2 group were significantly higher[D-lactic acid(ng/mL) 139.49 ± 28.83, 135.75 ± 25.19 vs 65.09 ± 33.16; TNF-α(pg/mL)358.60(314.18, 395.73),312.25(275.75, 345.40) vs 65.85(47.82, 84.32); all P<0.05], TNF-α value and D-lactic acid level showed increased trend in CORM-2 group, but it's not statistically significant[ D-lactic acid(ng/mL) 75.65±34.14 vs 65.09±33.16; TNF-α(pg/mL) 104.00(93.10, 131.95) vs 65.85(47.82, 84.32); all P>0.05]. The levels of D-lactic acid and TNF-αin the CORM-2 group were lower than those in the shock group and iCORM-2 group (all P<0.05). Conclusions CORM-2 may reduce the intestinal barrier damage by anti-inflammatory effects and up-regulate the expression of tight junction proteins in the intestinal epithelium.