[Establishment of β-aminopropionitrile-induced aortic dissection model in C57Bl/6J mice].

Objective To establish the mouse aorta dissection (AD) model through drinking water containing β-aminopropionitrile (BAPN). Methods Forty 3-week-old C57B1/6J male mice were divided into four groups according to randomized block design: control, 0.2, 0.4 and 0.8 g·kg-1·d-1 BAPN groups (dissolving respective dose of BAPN in the drinking water, n=10 each group). Arterial systolic blood pressure and heart rate were measured weekly in conscious, restrained mice using a noninvasive computerized tail-cuff system. Mice those died of rupture of aortic dissecting aneurysm during the study were autopsied and the aorta was examined. After 4 weeks, survived mice were sacrificed by an overdose of sodium pentobarbital and the whole aorta was harvested and analyzed. Results The incidence of AD and the mortality of ruptured AD was 0 and 0 in control group, 30% (3/10) and 20% (2/10) in 0.2 g·kg-1·d-1 BAPN group, 50% (5/10) and 40% (4/10) in 0.4 g·kg-1·d-1 BAPN group, 90% (9/10) and 70% (7/10) in 0.8 g·kg-1·d-1 BAPN group (both P<0.05 vs. control group). The incidence of AD and the mortality of ruptured AD increased in proportion to BAPN concentration increase. In 0.8 g·kg-1·d-1 BAPN group, 7 mice died of dissecting aneurysm rupture during the experiment, among which 5 dissecting aneurysms were mainly located in the thoracic aorta and 2 dissecting aneurysms in abdominal aorta. The diameters of thoracic aorta and abdominal aorta were (1.38±0.19) and (1.23±0.13) mm in control group, (2.43±1.56) and (1.30±0.26) mm in 0.2 g·kg-1·d-1 BAPN group, (2.45±1.28) and (1.30±0.31) mm in 0.4 g·kg-1·d-1 BAPN group, (2.87±0.57) and (1.95±0.81) mm in 0.8 g·kg-1·d-1 BAPN group (both P<0.05 vs. control group). The diameters of thoracic aorta and abdominal aorta in mice also increased in proportion with BAPN concentration increase. Furthermore, blood-filled false lumen formation and elastic fibers fragmentation were evidenced in hematoxylin-eosin stained and Vitoria blue-Sirius red stained aortic cross-sections of mice in the 0.8 g·kg-1·d-1 BAPN group. Conclusion BAPN treatment induced aortic dissection model in C57Bl/6J mice can serve as a useful wild-type mouse model for the mechanism and pharmaceutical studies of AD. Key words: Aneurysm,dissecting; Aminopropionitrile; Models, animal; Mice