Objective To investigate the role of Rho kinase (ROCK) in the protective effects of hydrogen on intestinal epithelial barrier function in sepsis. Methods Caco-2 cells were cultured routinely, and divided into 6 groups randomly (n=3):control group (C group), hydrogen-rich medium group (H group), lipopolysaccharide (LPS)-treatment group (L group), hy⁃drogen+LPS-treatment group (HL group), Rho kinase inhibitor (Y-37632) treatment group (Y group) and Rho kinase inhibi⁃tor Y-27632+LPS-treatment group (YL group). H group was treated with 0.6 mmol/L hydrogen-rich media. The concentra⁃tion of LPS and Y-27632 were 50 mg/L and 25μmol/L separately. After the Caco-2 monolayer model was established, the transepithelial electrical resistance (TEER) values were measured regularly. When the TEER value reached 800Ω·cm2, the treatment was administered. Then TEER values were measured at 6 h, 12 h and 24 h, and FITC-dextran permeability was de⁃tected at 24 h. Cells were seeded on 6-well plates. After cell density reached 80%-90%, treatments were given randomly. The real time-polymerase chain reaction (RT-PCR) was conducted to assess mRNA levels of ZO-1 and ROCK mRNA. ZO-1 and ROCK protein expression levels were detected by Western blot assay. Results Compared with C group, TEER values were elevated in 12 h and 24 h in H group (P<0.05). There were no statistical significances in FITC-dextran permeability, protein expression levels of ZO-1 and ROCK between C group and H group (P>0.05). TEER values were elevated at 6 h, 12 h and 24 h in Y group (P<0.05). There was no significant difference in FITC-dextran permeability between C group and Y group (P > 0.05). The mRNA expression of ZO-1 increased and mRNA expression of ROCK decreased in Y group (P <0.05). The TEER values reduced at 6 h, 12 h and 24 h in L group. The FITC-dextran permeability increased significantly, mRNA and protein expressions of ZO-1 significantly decreased, mRNA and protein expressions of ROCK significantly in⁃creased in L group (all P<0.05). Compared with L group, TEER values increased significantly at 6 h, 12 h and 24 h in YL group, FITC-dextran permeability decreased, mRNA expressions of ZO-1 increased, mRNA expressions of ROCK de⁃creased in YL group (P<0.05). Compared with L group, TEER values increased at 6 h, 12 h and 24 h in HL group, FITC-dextran permeability reduced markedly, protein expressions of ZO-1 increased at each time point, protein expressions of ROCK decreased at each time point in HL group (P<0.05). Conclusion Hydrogen can protect intestinal barrier function against sepsis, ameliorate the integrity and permeability of intestinal epithelium and increase the expressions of intercellular tight junction proteins. The suppression of Rho kinase over-expression induced by LPS may be involved in these protective effects of hydrogen.%目的：探讨Rho激酶（ROCK）在氢气改善离体脓毒症肠屏障功能中的作用。方法常规培养人结肠上皮细胞Caco-2，分为6组（n=3）：对照组（C组）、富氢培养基组（H组）、脂多糖（LPS）处理组（L组）、富氢培养基+LPS组（HL组）、Rho激酶抑制剂Y-27632组（Y组）、Y-27632+LPS组（YL组）。H组给予0.6 mmol/L富氢培养基；LPS和Y-27632的处理浓度分别为50 mg/L、25μmol/L。建立Transwell小室模型，定期检测跨上皮电阻值（TEER值），当TEER值达到800Ω·cm2后给予处理，于6、12、24 h检测TEER值，24 h时检测FITC-右旋糖酐通过率。细胞接种于6孔板，融合达80%~90%后给予处理，实时聚合酶链式反应技术检测闭锁小带蛋白1（ZO-1）mRNA和ROCK mRNA表达情况；蛋白免疫印迹技术检测ZO-1蛋白和ROCK蛋白表达水平。结果与C组比较，H组12、24 h TEER值升高（P＜0.05），FITC-右旋糖酐通过率、ZO-1蛋白和ROCK蛋白表达水平差异无统计学意义；Y组6、12、24 h TEER值升高（P＜0.05），FITC-右旋糖酐通过率差异无统计学意义，ZO-1 mRNA表达增加，ROCK mRNA表达减少（均P＜0.05）；L组6、12、24 h TEER值降低，FITC-右旋糖酐通过率增高，ZO-1 mRNA和蛋白表达均下降，ROCK mRNA和蛋白表达均增加（P＜0.05）。与L组比较，6、12、24 h YL组TEER值增高，FITC-右旋糖酐通过率降低，ZO-1 mRNA表达增加，ROCK mRNA表达降低（均P＜0.05）。与L组比较，HL组6、12、24 h TEER值增高，FITC-右旋糖酐通过率降低，各时间点ZO-1蛋白表达上升，ROCK蛋白表达下降（均P＜0.05）。结论氢气可保护脓毒症肠屏障功能，改善肠上皮屏障完整性和通透性，增加肠细胞间紧密连接蛋白表达，这些保护机制可能与氢气抑制LPS诱导的ROCK过度表达有关。
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