摘要目的 研究氢气饱和生理盐水对大鼠腹主动脉瘤(AAA)形成的作用,探讨其抑制AAA的机制.方法 对20只雄性SD大鼠行氯化钙孵育肾下腹主动脉制成AAA模型,随机分为2组:实验组10只腹腔内注射氢气饱和生理盐水(5 ml· kg-1·d-1),对照组10只注射生理盐水.28 d后观察两组主动脉扩张情况,并用HE染色及醛品红溶液染色检测主动脉壁内炎性细胞浸润及中膜弹力纤维破坏情况,ELISA检测瘤壁IL-1β、肿瘤坏死因子α(TNF-α)浓度,免疫组化观察动脉瘤组织基质金属蛋白酶2、9(MMP-2、9)的蛋白表达,real-time PCR测定MMP-2、9的基因表达.结果 实验组与对照组腹主动脉最大直径为(2.2 ±0.3)mm和(3.4±0.5)mm,瘤壁IL-1β浓度为(81±29) ng/L和(165 ±51)ng/L,TNF-α浓度为(109 ±46)ng/L和(360 ±51)ng/L,MMP-2 mRNA相对表达量为2.4±1.0和11.8±2.9,MMP-9 mRNA相对表达量为2.9 ±0.6和6.7±1.0,差异有统计学意义(t=4.055 ～ 10.406,P均＜0.05).实验组动脉壁弹力纤维未见明显受损,仅有少量炎性细胞浸润及MMP-2、9弱阳性表达.对照组动脉壁弹力纤维严重受损,可见明显炎性细胞浸润,MMP-2、9强阳性表达.结论 氢气饱和生理盐水可能通过改善炎性细胞浸润、减少炎性介质释放,降低MMP-2、9的mRNA表达、蛋白合成,从而抑制大鼠腹主动脉中膜弹力纤维的降解和退变,最终抑制AAA的形成.

abstractsObjective To investigate the effects of saturated hydrogen saline on the prevention of abdominal aortic aneurysm (AAA) induced by calcium chloride in a rat model.Methods In healthy male Sprague-Dawley rats,AAA was induced by infiltration of abdominal arota with 0.5 mol/L calcium chloride.Saturated hydrogen saline (5 ml · kg-1 · d-1) or saline was administred intraperitoneally once daily.Twenty-eight days later,the diameter of the aorta was measured,and the aortic tissue was exercised for histological examination.Pro-inflammatory cytokines (tumor necrosis factor α (TNF-α),IL-1β) in AAA tissue were detected with ELISA.The protein expression and mRNA expression of matrix metalloproteinase 2(MMP-2) and MMP-9 in AAA tissue were observed by immunohistochemistry staining and real-time PCR.Results The aorta diameter of the experiment group and control group were (2.2 ± 0.3) mm and (3.4 ±0.5) mm,the tissue IL-1β levels were (81 ±29) ng/L and (165 ±51) ng/L,the tissue TNF-α levels were (109 ±46) ng/L and (360 ±51) ng/L,the relative mRNA expressions were 2.4 ± 1.0 and 11.8 ±2.9,the relative mRNA expressions were 2.9 ±0.6 and 6.7 ± 1.0 (t =4.055 to 10.406,P ＜0.05).Compared with the control group,the infiltration of inflammation,the injury of elastic fibers in the vessel wall,and the positive expression of MMP-2 and 9 protein of the experiment group were all reduced.Conclusions Saturated hydrogen saline prevents the degradation of elastin in vessel wall and ameliorates the formation and development of AAA,which may be associated with its anti-inflammatory effects,thereby reduces the MMP-2 and 9 mRNA and protein expression.