Abstract 404: Cilostazol Attenuated Angiotensin II-Induced Abdominal Aortic Aneurysms in Apolipoprotein E--Deficient Mice
Objective: Chronic infusion of angiotensin II (AngII) promotes development of abdominal aortic aneurysms (AAAs) in hypercholesterolemic mice. Previous studies have shown that local inflammation and increased oxidative stress plays an important role on formation of AAAs. Cilostazol, a phosphodiesterase-3 inhibitor with antiplatelet aggregation and vasodilatory effects, exerts vasoprotective effect by inhibiting inflammation and superoxide generation in several experimental studies. The purpose of this study was to evaluate whether cilostazol influenced AngII-induced AAAs.
Methods and Results: Male apolipoprotein E deficient mice (8-12 weeks old) were fed with either normal diet or cilostazol-containing (0.1% wt/v) diet. After 1 week of cilostazol administration, mice were infused subcutaneously with either AngII (1,000 ng/kg/min, n = 16 -18) or saline (n = 5 - 6) by osmotic minipumps for 4 weeks. AngII equivalently increased systolic blood pressure, irrespective of cilostazol adminstration. Cilostazol had no effect on serum cholesterol concentrations, triglycerides, high-density lipoprotein-cholesterol, body weights, heart rates, and systolic blood pressures. Cilostazol did not affect ex vivo measurement of maximal diameter of abdominal aorta (0.88 ± 0.04 mm vs 0.88 ± 0.03 mm, n.s.) in saline infused-mice. AngII infusion significantly increased ex vivo maximal diameters of abdominal aortas but cilostazol administration attenuated (1.94 ± 0.16 mm vs 1.53 ± 0.17 mm, P < 0.05). In addition, gelatin zymography demonstrated that cilostazol diminished AngII-induced increase in aortic MMP-2 activity (P < 0.05).
Conclusion: Cilostazol attenuated AngII-induced AAAs in male apolipoprotein E deficient mice.
- © 2012 by American Heart Association, Inc.