脑肠肽Ghrelin对脓毒症大鼠肠道功能障碍的影响

Effect of brain-gut peptide Ghrelin on intestinal dysfunction in septic rats

目的探讨脑肠肽Ghrelin对脓毒症大鼠肠道功能障碍的作用。方法大鼠随机分为正常对照组、假手术组、脓毒症组和Ghrelin组。用苏木精-伊红染色观察肠道组织病理形态学改变,用免疫组织化学方法观察Ghrelin表达量,用硫代巴比妥酸综合法测定丙二醛(MDA),用黄嘌呤氧化酶法测定超氧化物歧化酶(SOD),用酯酸还原法测定一氧化氮合成酶(NOS)。酶联免疫吸附法测定炎症因子肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)和白细胞介素-6(IL-6)的表达,用肠道通透性实验评估肠道黏膜功能。结果脓毒症组大鼠小肠Ghrelin的表达降低。脓毒症组TNF-α、IL-1β和IL-6较正常对照组增高[TNF-α:(175.73±19.39)比(62.05±8.71)pg/mL,P<0.01;IL-1β:(49.07±5.41)比(24.62±2.85)pg/mL,P<0.01;IL-6:(39.22±4.65)比(17.95±2.47)pg/mL,P<0.01],而Ghrelin组较脓毒症组降低[TNF-α:(67.88±8.04)比(175.73±19.39)pg/mL,P<0.01;IL-1β:(20.95±2.78)比(49.07±5.41)pg/mL,P<0.01;IL-6:(16.05±1.92)比(39.22±4.65)pg/mL,P<0.01]。Ghrelin组SOD表达较脓毒症组增加[(61.33±7.07)比(28.85±3.19)U/mL,P<0.01],而NOS和MDA表达明显降低[NOS:(5.71±0.73)比(2.99±0.41)U/mL,P<0.01;MDA:(5.05±0.63)比(1.77±0.28)nmol/mL,P<0.01]。肠道通畅性实验显示,Ghrelin可改善肠道黏膜屏障障碍。结论Ghrelin通过控制炎症反应,减轻氧化应激,降低肠黏膜通透性而改善脓毒症大鼠的肠道功能障碍。

Objective To investigate the effect of brain-gut peptide Ghrelin on intestinal dysfunction in septic rats.Methods The rats were randomly divided into the normal control group,the sham operation group,the septic group and the Ghrelin group.The pathomorphological changes in intestinal tissues were observed by hematoxylin and eosin staining,and the expression of Ghrelin was determined by immunohistochemistry.Malondialdehyde(MDA)was determined by the thiobarbituric acid condensation method.Superoxide dismutase(SOD)was determined by the xanthine oxidase method.Nitric oxide synthase(NOS)was determined by the nitrate reductase method.Tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β)and interleukin-6(IL-6)were determined by an enzyme-linked immunosorbent.The intestinal mucosal function was evaluated by an intestinal permeability test.Results Immunohistochemistry showed that the expression of Ghrelin in small intestine of sepsis group rats was decreased.TNF-α,IL-1βand IL-6 in the sepsis group were higher than those in normal control group[TNF-α:(175.73±19.39)vs(62.05±8.71)pg/mL,P<0.01;(49.07±5.41)vs(24.62±2.85)pg/mL,P<0.01;IL-6:(39.22±4.65)vs(17.95±2.47)pg/mL,P<0.01],and the Ghrelin group was lower than the sepsis group[TNF-α:(67.88±8.04)vs(175.73±19.39)pg/mL,P<0.01;IL-1β:(20.95±2.78 vs(49.07±5.41)pg/mL,P<0.01;IL-6:(17.95±2.47)vs(39.22±4.65)pg/mL,P<0.01].Compared with the sepsis group,SOD expression in the Ghrelin group was increased[(61.33±7.07)vs(28.85±3.19)U/mL,P<0.01],while NOS and MDA expression were significantly decreased[NOS:(5.71±0.73)vs(2.99±0.41)U/mL,P<0.01;MDA(5.05±0.63)vs(1.77±0.28)nmol/mL,P<0.01).The intestinal permeability test showed that Ghrelin improved the barrier of intestinal mucosa.Conclusion Ghrelin can improve intestinal dysfunction in septic rats by controlling inflammatory reaction,reducing oxidative stress and intestinal mucosal permeability.