Comparison between two types of middle cerebral artery occlusion model in mice by monofilament method

Abstract

Objective To establish a model of transient middle cerebral artery occlusion (MCAO) in mice by inserting monofilament through common carotid artery and external carotid artery embolization, and to compare and analyze the survival rate, behavior, infarct volume, brain edema degree and neuronal apoptosis of the two models. In order to select a more feasible and effective method for establishing cerebral infarction model. Methods Forty-two C57BL/6 male mice weighing 20-22 g were randomly divided into sham-operated group (6 mice, S-group), MCAO model external carotid artery catheterization group (18 mice, E-group) and MCAO model common carotid artery catheterization group (18 mice, C-group). E-group prepared a mice model of middle cerebral artery embolism from the beginning of middle cerebral artery embolization by inserting a monofilament embolism into the external carotid artery shear. C-group prepared a mice model of middle cerebral artery embolism from the beginning of middle cerebral artery embolization by inserting a monofilament embolism into the common carotid artery shear. The S- group was ligated with the ipsilateral common carotid artery of the model group, but no monofilament was inserted as the control group. After 1 h of ischemia in model group and 1 h of ligation in S-group, the ligation of common carotid artery was removed and the ligation was reperfused for 24 h. Later, Longa nerve function score was used and TTC staining was performed to calculate the infarction volume, measure the water content of brain tissue and observe the neuronal apoptosis, and then the comparative analysis was made. Results In both E-group and C-group, apoplexy, elevated neurological function score, brain edema, obvious infarct volume and neuronal apoptosis were observed in all mice, while in S-group, there were no obvious manifestations. Compared with the E-group, the infarction volume and the degree of brain edema in both group was close, and the number of apoptotic neurons was basically the same. The difference has no statistical significance (P>0.05). Compared with the E-group, the C-group had a higher score of neurological function and a higher mortality rate, with statistical significance(P<0.05). Conclusion The results of cerebral infarction caused by two kinds of embolization are consistent, but considering that some experiments need long-term administration and observation, and the survival rate of experimental animals in E-group is higher, so it is recommended to use external carotid artery embolization method to make middle cerebral artery embolization model. Key words: Middle cerebral artery occlusion; External carotid artery; Common carotid artery; Monofilament method