Osmotic minipump

Male ApoE^−/− mice were purchased from Charles River in Beijing. Age-matched male α7nAChR^−/− mice (Stock number: 003232) and WT mice were purchased from Jackson Laboratory in USA, and bred in our animal facility. All mice were housed under a relative humidity about 50%, constant temperature (22–25 °C), standard light conditions (12 h-light/12 h-dark cycle) and were free to food and water. The whole experimental procedures were approved by the Institutional Animal Care and Use Committee of Tongji University and in accordance with the Guide for the Care and Use of Laboratory Animals, which was published by the Ministry of Health, People’s Republic of China and National Institutes of Health.
Male ApoE^−/− mice (about 6-month-old), male WT and α7nAChR^−/− mice (about 12-month-old) were used to induce AAA formation by Ang II. Briefly, mouse was anesthetized with pentobarbital sodium (50 mg/kg, ip) and implanted with an osmotic minipump (#2004#, Durect corporation, USA), which could deliver Ang II at a rate of 1000 ng·kg⁻¹·min⁻¹ for 4 week successively. PNU-282987 (1 mg·kg⁻¹·d⁻¹, ip) was injected to activate α7nAChR in ApoE^−/− mice. Four weeks after surgery, mice were killed after anesthesia to obtain the abdominal aorta for analysis. An aneurysm was defined by at least 50% dilation in the diameter of abdominal aorta from Ang II-infused mice as compared with the control.