Establishment of a model of carotid atherosclerotic stenosis in rabbits and the expression of asparaginyl endopeptidase / 中国脑血管病杂志

ABSTRACT

Objectives To establish a model of carotid atherosclerotic (AS)stenosis in rabbits and to preliminarily investigate the expression of asparaginyl endopeptidase. Methods Fourteen New Zealand white rabbits were divided into either an model group (n = 8)or a sham operation group (n = 6)according to the random number table. The carotid intima was injured by operation in the model group. The rabbits in both groups were fed with high fat diets containing magnesium for 10 weeks. The rabbits were weighted and their blood lipids were tested every 2 weeks. At the end of the fifth and tenth weeks after procedure,the plaque and vessel stenosis of the rabbits were observed by MRI. At the end of the tenth week after proce-dure,the specimens were collected and sliced. Hematoxylin and eosin (HE)staining was used to observe the pathological changes. Immunohistochemical staining was used to analyze the expression of asparaginyl endopeptidase (AEP). Results One rabbit in the model group died of carotid artery injury. After being fed with high-fat diets,the body quality and the level of blood lipid were increased in the rabbits of both groups compared with those before procedure (all P < 0. 01). At the end of the fifth and tenth weeks after procedure,MRI revealed that the luminal stenosis rates in the operation group were 16 ± 11% and 53 ± 20% respectively. There was significant difference within the group (t = - 4. 83,P < 0. 01). MRI revealed no luminal stenosis twice in the sham operation group. HE staining showed intimal hyperplasia,AS plaque formation,lipid deposition in plaques,macrophage and smooth muscle cells migration and infiltration forming foam cells in the model group. No AS formation was observed in the sham operation group. The expression of AEP was higher in the rabbit carotid artery tissue in the model group,and it expressed rarely in the sham surgery group. The absorbance values were 0. 072 0 ± 0. 028 0 and 0. 002 0 ± 0. 000 9 respectively. There was significant difference (t = 6. 61,P < 0. 01). Conclusions The methods of injuring carotid intima combined with magnesium containing high-fat diet may exactly,reliably,and quickly establish an AS carotid artery stenosis model. AEP may associat with the occurrence of AS plaques.