Vascular Smooth Muscle Proliferation And Migration Role In Atherosclerosis Research

Part One:Proliferation and migration of vascular smooth muscle and research of animal model of atherosclerosis.Objective:To establish a model of smooth muscle cell proliferation and migration in New Zealand white rabbit carotid artery endothelial injury.Materials and Methods:20New Zealand white rabbits, divided into two groups, DSA surgery them by repeated expansing the right carotid artery with2.5F or4.OF balloons, then feed them with high fat diet (containing2%cholesterol). The model animals were executed at2weeks,4weeks,6weeks,8weeks and10weeks. Specimens of carotid artery is taken to do a biopsy, Proliferation and migration of vascular smooth muscle cells will be observed through HE staining.Results:2.5F balloon can cause mild damage to the arterial endothelium, vascular membrane damage is not obvious, four weeks after surgery proliferation and migration of smooth muscle cell is not obvious. After4.OF balloon dilation, the vascular endothelium was destroyed and extensive damaged associated with vascular medial smooth muscle cells, vascular smooth muscle cell proliferation and migration significantly after two weeks, the lumen was narrowing with high-fat feeding. Eight weeks after surgery, atherosclerotic plaques can be observed. Pathology showed the difference between two groups in vessel wall thickening and the degree of stenosis of the lumen, there was statistic difference (p<0.05).Conclusion:2.5F balloon is fit for the experiment of AS animal model. Proliferation and migration of vascular smooth muscle cells can be successfully obtained in animal models, and can be used to study the pathology of vascular smooth muscle cells. Part Two:proliferation and migration of vascular smooth muscle cells after vascular endothelial injuryObjective:To observe and analyze the pathological changes of proliferation and migration in vascular smooth muscle cell after injury.Materials and Methods:10New Zealand white rabbits,2.5F balloon injure right carotid artery, feed with high-fat diet. Specimens of carotid arteries are taken2,4,6,8weeks after balloon injury, then do a pathology research.Results:24hours after the vascular endothelial injury, inflammatory cell infiltration and migration is observed. In two weeks, the vascular smooth muscle cells proliferation and migration;4-8weeks, intimal thickening, vascular stenosis; eight weeks after the injury, the formation of atherosclerotic plaque and vascular stenosis are observed. Synthetic smooth muscle cells decreased significantly. Atherosclerotic plaques are fragile.Conclusion:After injury of the vascular endothelial, proliferation and migration of VMCs are the main reason for vascular stenosis, atherosclerotic plaque formation. Study the pathology can provide a course to prevent restenosis and atherosclerotic plaque formation. Part Three:Study of MR imaging of the vessel wall after balloon injury.Objective:To study the pathological changes of the vessel wall after vascular endothelial injury. compare with MRI findings.Materials and Methods:Artery balloon angioplasty injury in10rabbits unilateral carotid artery. feed with high-fat diet for10weeks. MRI imaging studies of the carotid artery are done at2,4,6,8and10weeks, compared with pathology findings.Results:2weeks after injury TOF image showed no significant stenosis, PD T1WI vessel wall showed middle signal. T2WI showed high signal.4and6weeks after injury, TOF vascular image showed no significant stenosis, PD, T1W1and T2WI showed intermediate signal.8,10weeks after injury, TOF vessel image showed progressive stenosis, PD T1WI showed intermediate signal, part of the T2WI images showed high signal.Conclusion:Changes can be observed in rabbit carotid arteries after balloon injury in the MR images. MRJ can reflected the luminal changes of blood vessels stenosis.