Elastase injection into the cerebellomedullary cistern to induce a model of vertebrobasilar dolichoectasia in mice and evaluation of magnetic resonance angiography / 国际脑血管病杂志

ABSTRACT

Objective:To investigate the effect of magnetic resonance angiography (MRA) in evaluating the mouse model of vertebrobasilar dolichoectasia (VBD) induced by injection of elastase into cerebellomedullary cistern.Methods:Twenty-four male C57/BL6 mice were selected. The mice in the elastase group ( n=12) were injected in the cerebellomedullary cistern with 2.5 μl of phosphate buffer containing 25 mU elastase, and the mice in the saline control group ( n=12) were injected with the same volume of normal saline. MRA examination of the brains of living mice was performed 2 weeks after modeling. Successful modeling was defined as the basilar artery bending angle ≤170°, or the basilar artery bending length accounts for ≥10%, or the basilar artery deviated from the midline by more than 1 grade, or the percentage increase in artery diameter was ≥25%. Results:In the elastase group and the saline control group, 2 mice and 1 mouse did not wake up normally or died, respectively. The 11 surviving mice in the saline control group had no obvious vertebral artery and basilar artery abnormalities. The success rate of modeling in the 10 surviving mice in the elastase group was 80%, and the difference in the success rate between the two groups was statistically significant ( P<0.05). There were significant differences in mean basilar artery diameter (0.30 mm vs. 0.22 mm; P<0.05), mean basilar artery bending angle (115° vs. 170°; P<0.05), and proportion of mean basilar artery bending length (31% vs. 5%; P<0.05) of the surviving mice between the elastase group and the saline control group. Conclusion:MRA can better evaluate the mouse VBD model induced by elastase injection in the cerebellomedullary cistern.