Effects Of Saturated Hydrogen Saline On Experimental Model Of Abdominal Aortic Aneurysm In Rats

【Objective】1. Establish an experimental model of AAA in rats through xenograft modified by “cuff”, and then evaluate its feasibility for researching the pathogenesis of AAA;2. In order to find a new strategy for treating AAA, the impact of saturated hydrogen saline to experimental model of AAA in rats was observed.【Methods】This project included two parts. In part one, experimental model of AAA(experimental group) was established through aortic xenograft. In this model, the decellulared thoracic aorta of guinea pig was severed as donor aorta. The donor aorta was transplanted into the subrenal aorta of SD rat, during which “cuff” was employed instead of aortic anatomosis. In control group, AAA was induced by infiltration of abdominal arota with calcium chloride. After establishment of models, the diameter of abdominal aorta was measured through doppler ultrasound termly. The feasibility of the experimental model of AAA in rats was evaluated by comparing the time for establishing a model, the AAA rate of models, the aorta expension rate of models and variation of histomorphology.In part two, experimental models of AAA were established and devided into experimantal group and control group randomly. Saturated hydrogen saline(5ml/kg) or saline(5ml/kg) was administred intraperitoneally every24hours in experimental group and control group respectively. The diameter of abdominal aorta was measured through doppler ultrasound termly. The impact of saturated hydrogen saline to experimental model of AAA was evaluated by comparing the variation fo aortic diametre, the AAA rate of models, survival condition and histomorphology of experimental group with that of control group.Histological stain included hemateineosin stain, elastic tissue stain and picric acid‐sirius red stain.【Results】1. In part one, experimental models of AAA were established successfully. The aneurysm expensional rate in experimental group was142±33%, and that of control group was61±27%, where the difference was significantly obvious. The aneurysm formation rate of experimental group was higher than that of control group(P＜0.01). The time of establishing a model was45.92±3.37min(experimental group) and32.58±1.73min(control group) respectively, which were significantly different. During the period of observation,4rats in experimental group died, and no rat died in control group. In the experimental group, the aortic wall was infiltrated by a lot of inflammatory cells, and the elastin was damaged seriously in the media.2. In part two, the aneurysm expensional rate was102±22%and142±21%inexperimental group and control group respectively,which were significantly different. No difference of aneurysm formation rate was observed between experimental group and control group. During the period of observation,2rats died in experimental group and5rats died in control group. Compared with control group, the aortic wall was infiltrated by less inflammatory cells, and the elastin was damaged less seriously in the experimental group.【Conclusion】1. Experimental model of AAA was characterized by a high AAA rate of models, obvious expension of AAA and tendency to rupture, and can be used to research the pathogenesis of AAA.2. The progress of AAA can be alleviated by hydrogen. The mechanism of protection was lowing inflammatory cells infiltration and lightening extracellular matrix remodeling.