To investigate the inhibitory effect and mechanism of aspirin combined with tigrelol on the growth of abdominal aortic aneurysm.

48 apolipoprotein E gene deficient mice for 36 days were randomly divided into 5 groups. Among them, 8 rats were in the normal saline control group, and the other 40 rats were induced by continuous subcutaneous injection of angiotensin Ⅱ(AngⅡ; 1000 ng·kg^-1·min^-1). According to different intervention methods, the 40 animals were divided into AngⅡ group, aspirin group, tegrerol group and aspirin combined with tegrerol group (dual drug combination group), with 10 rats in each group. The basic information of mice in each group were recorded before and at the end of the experiment, including body weight, systolic blood pressure, total cholesterol, triglyceride, platelet count, etc. The tissue of abdominal aorta was obtained, and interleukin-1β (IL-1β), tumor necrosis factor α (TNF-α), matrix metalloproteinase (MMP)-2 and MMP-9 were detected by immunohistochemistry and western blot. Univariate analysis of variance was used for comparison of measurement data between multiple groups, and LSD-t test was used for further comparison between the two groups.

There was no significant difference in total cholesterol, triglyceride, systolic blood pressure and platelet count between the five groups (P > 0.05), but there was significant difference in systolic blood pressure at the end of the experiment (F=53.670, P < 0.05). Except that the control group did not form abdominal aortic aneurysm, the modeling rate of abdominal aortic aneurysm in the other four groups was 50.0%~80.0%, and the rupture rate was 30.0%~50.0%. There was significant difference in the diameter of abdominal aortic aneurysm among the five groups (F=25.470, P < 0.05), and the diameter of abdominal aortic aneurysm in AngⅡ group, aspirin group and tigrelol group was significantly larger than that in the combination group (P < 0.05 or P < 0.01). The expression levels of IL-1β, TNF-α, MMP-2, MMP-9 in 5 groups were significantly different (F=45.500, 21.940, 49.650, 199.100, P < 0.05 or P < 0.01). The expression levels of all indexes in the two-drug combination group were significantly lower than those in the AngⅡ group, aspirin group and ticagrelor group (P < 0.05), and there was no significant difference in the expression levels of all indexes in aspirin group and ticagrelor group compared with the AngⅡ group (P > 0.05).

Aspirin combined with ticagrelor can inhibit the formation and growth of abdominal aortic aneurysm in mice, which may be related to the inhibition of inflammatory response in abdominal aorta.