硫化氢对脓毒症大鼠膈肌功能障碍的保护作用

Protective effect of hydrogen sulfide on diaphragmatic dysfunction in septic rats

目的研究硫化氢对脓毒症大鼠膈肌收缩功能、膈肌组织炎性因子、氧化应激指标及膈肌超微结构的影响。方法 36只清洁级健康雄性SD大鼠,按完全随机分组法分为对照组、模型组和观察组,每组12只。对照组予以生理盐水腹腔注射,模型组及观察组均予以脂多糖(LPS)腹腔注射造模,观察组在造模后半小时予以硫氢化钠(NaHS)腹腔注射。24 h后,各组大鼠取新鲜膈肌组织,其中随机选取8只大鼠的膈肌组织,检测收缩功能,肿瘤坏死因子-α(TNF-α)、白介素(IL-6)和丙二醛(MDA)及超氧化物歧化酶(SOD)的含量。余下4只大鼠的膈肌组织制作为电镜标本,观察其在电镜下的超微结构。结果模型组膈肌肌张力及最大强直肌力较对照组显著降低,观察组膈肌肌张力及最大强直肌力显著高于模型组。观察组促炎因子TNF-α、IL-6水平及氧自由基MDA含量较模型组显著降低,SOD消耗明显减少(P <0.05或P <0.01)。模型组膈肌肌纤维超微结构破坏,观察组较模型组显著改善。结论硫化氢供体NaHS在LPS诱导的膈肌功能障碍中起到保护作用。原因可能是硫化氢通过下调膈肌炎症因子并减少氧自由基的释放,抑制膈肌纤维超微结构的改变,进而改善脓毒症时膈肌功能障碍。

Objective To investigate the effect of hydrogen sulfide on diaphragmatic contractile function,inflammatory cytokines,oxidative stress and the ultrastructure changes of diaphragm muscle fibers.Methods A total of 36 male SpragueDawley(SD) rats were randomly assigned into three groups:control group(n=12),model group(n=12)and obsevation group(n=12).Rats in the control group were given intraperitoneal injection of normal saline.LPS was used to establish the animal model in the other two groups,and the observation group was given intraperitoneal injection of sodium hydrosulfide hydrate half an hour after modeling.After 24 h,the fresh diaphragm in control group rats was removed.The diaphragm tissues of 8 rats were randomly selected,which were used for diaphragm contractile function test,detecting the pro-inflammatory cytokines TNF-α,the IL-6 and oxidative stress indexes of MDA and the SOD content.The diaphragm tissues of the remaining 4 rats were made into specimens for observing the ultra structural of muscle fiber under the electron microscopy.Results The diaphragmatic muscle tension and maximum tonic muscle strength in model group were significantly lower than those in control group.The diaphragmatic contractility at each frequency stimulation and maximum tetanic force in observation group was significantly higher than that in model group(P<0.05).Comparing with the model group,the pro-inflammatory cytokines TNF-α and IL-6 in observation group were significantly decreased(P<0.05),the MDA content was decreased significantly(P<0.05) and the SOD consumption was also significantly reduced(P<0.05).The ultrastructure of diaphragm muscle fibers in model group was damaged,and in observation group was significantly improved vs model group.Conclusion Sodium hydrosulfide hydrate as hydrogen sulfide donor plays a protective role in LPS induced diaphragm dysfunction.Hydrogen sulfide improves sepsis diaphragmatic dysfunction significantly maybe through downregulating inflammatory cytokines level and reducing the release of oxygen free radicals,inhibiting the ultrastructure changes of diaphragm muscle fibers.