氢气饱和生理盐水对腹主动脉瘤大鼠主动脉残余应力的影响

A STUDY ON RESIDUAL STRAIN OF ABDOMINAL AORTIC ANEURYSM AFTER INTRAPERITONEAL ADMINISTRATION OF SATURATED HYDROGEN SALINE IN RATS

目的通过观察腹主动脉瘤(abnormal aortic aneurysm,AAA)大鼠腹主动脉直径、扩张率、血管壁厚度及张开角等指标的变化,了解氢气饱和生理盐水对AAA大鼠主动脉残余应力的影响,探讨其对AAA形成的抑制作用。方法选取健康雄性SD大鼠20只(体重200～220 g),采用肾下腹主动脉CaCl2孵育法制备大鼠AAA模型,随机分为实验组和对照组,每组10只。建模后当天开始,实验组于腹腔注射氢气饱和生理盐水(5 mL/kg),对照组注射生理盐水(5 mL/kg);每天1次,共28 d。建模后28 d处死两组动物,测量腹主动脉直径并计算扩张率,选取瘤体位置动脉环测量腹主动脉张开角及血管壁厚度,并对标本行HE染色和醛品红弹力纤维特殊染色观察主动脉壁炎性细胞浸润及中膜弹力纤维破坏情况。结果建模后28 d,实验组与对照组腹主动脉直径均较术前显著增加(P<0.01);扩张率分别为65%±15%和128%±54%,实验组显著低于对照组(t=3.611,P=0.005)。实验组与对照组腹主动脉张开角分别为(88.78±29.20)°和(44.23±28.52)°,血管壁厚度分别为(0.14±0.03)mm和(0.36±0.05)mm,两组比较差异均有统计学意义(P<0.01)。组织学观察示,实验组主动脉壁存在少量炎性细胞浸润,弹力纤维未见明显受损;对照组主动脉壁炎性细胞浸润明显,弹力纤维断裂受损严重。结论氢气饱和生理盐水通过增大主动脉的残余应力、减轻血管壁的组织重建程度,来维持腹主动脉更好的力学特性,减少腹主动脉扩张,抑制AAA的形成。

Objective By observation of the diameter, progression rate, wall thickness, and the opening angle of the abnormal aortic of abdominal aortic aneurysm （AAA） in rats, to observe the effect of saturated hydrogen saline on residual strain of AAA rats, and to investigate its inhibition effect on AAA formation. Methods Twenty healthy male Sprague Dawley rats （weighing, 200-220 g） were randomly divided into 2 groups, which was made the AAA model by infiltration of the abdominal arota with 0.5 mol/L calcium chloride. Saturated hydrogen saline （5 mL/kg） or saline （5 mL/kg） was injected intraperitoneally in the experimental group or control group respectively, every day for 28 days. At 28 days, the diameter, progression rate, wall thickness, and opening angle of the abnormal aorta were mearsured. The aortic tissue was harvested for histological examination （HE staining and aldehyde-fuchsin staining）. Results At 28 days after operation, the diameter of abnormal aorta in 2 groups were significantly higher than preoperative ones （P 〈 0.05）, the progression rate in experimental group （65% ± 15%） was significantly lower than that in control group （128% ± 54%） （t=3.611, P=0.005）. The opening angle and the wall thickness in experimental group were （88.78 ± 29.20）° and （0.14 ± 0.03） mm respectively, had significant differences when compared with the values in control group [（44.23 ± 28.52）° and （0.36 ± 0.05） mm respectively] （P 〈 0.01）. The integrity and continuity of the aortic wall in experimental group were superior to that in the control group. Compared with the control group, the injury of elastic fiber in aortic wall and the infiltration of inflammation were all reduced. Conclusion Saturated hydrogen saline can maintain good mechanical properties and reduce dilatation of the aorta by increasing residual strain and reducing the remodeling of it.