Inhibitory Effects Of Aspirin, Simvastatin, And Their Combination On The Progression Of Atherosclerosis In Rabbits

Objective:Atherosclerosis model were established by feeding high cholesterol diets(80% standard forage with 14% egg powder,1%cholesterol and 5%1ard).The purpose of the experiment is to compare the effect of aspirin,simvastatin,and their combination on the progression of atherosclerosis in New Zealand White rabbits and discuss the mechanism.Methods: 40 male New Zealand White rabbits were randomly distributed into 5 groups after one week by their serial number of weight. Every group has eight rabbits.The first group(N group) was fed with standard forage; The second group(H group) was fed with high cholesterol diets;The third group (A group) was was fed with high cholesterol diets and infused with aspirin (12mg/kg*d); The fouth group (S group) was was fed with high cholesterol diets and infused with simvastatin (5mg/kg*d); The fifth group (A+S group) was was fed with high cholesterol diets and infused with simvastatin (5mg/kg*d) and aspirin(12mg/kg*d). At the end of 6 weeks all rabbits' blood fat and C-reavtive protein were measured by BECKMAN LX2 automatic biochemistry analyzer and define protein analysator. To todepe in vein with urethane of 20%,to get general sample of aorta(from adjion aortic arch to celiac the brance of tyunk),fellow dorsal surface to split,pave nicely,take picture.Apply image analysator to determin plaque area,endomembranearea area,and to calculate plaque area/endomem- branearea area;To choose aorth descendens adjion aortic arch,to fix it in the paraformaldehyde of 4% for 72 hours,to paraffin imbedding,to do HE staining macrophage cells immunohistoch- emistry of blood vessels section continuous lice of 4um separately.To observe the changing of scleretheroma of aorta wall in every group by optics microscope;The positive percentage of macrophage cells were analyzed by immuno- histochemistry:apply S-P method DAB coloration,buffy granulo-product is masc symbol.To select 5 fields of vision randomly in every group,the percentage of positive staining is masc area/endothelium area.Then to do image analysis。Results: Hyperlipemia model and atherosclerosis model were confirmed by according to pathology and blood fat results. There was no significant difference on blood fat between H group and A group;Compared with H group, the blood fat of A group and A+S group reduced significantly;There was no significant difference on blood fat between S group and A+S group,but there was a trend ,not significantly, to lower blood fat in A+S group. Compared with H group,the CRP of A group,S group and A+S group reduced significantly; Compared with A group and S group, the CRP of A+S group reduced significantly. Observation by naked eye: The aorta endomembrane of N group was of smooth and endodermis series; The aorta endomembrane of H group is thickening obviously.The lipoids in plaque which contains generous foam cells is increasing.There is visible atheromatous plaque on the surface of endomembrane. Endo-elastic bord and tunica media elastic bord is degeneratin,break and disintegrate.Conclusions: New Zealand White rabbits fed with high lipoid diet showed higher numerical value of blood fat and thickening roughly endomembrane,plaque which contains generous foam cells outpocketing endomembrane surface liking grana.Endo-elastic bord and tunica media elastic bord is degeneratin,break and disintegrate.Aspirin didn't significantly change blood fat of rabbits.There was a trend,not significantly,to lower blood fat and plaque area/endomem branearea area in the combination of simvastatin and aspirin compared with single simvastatin.Not only aspirin but also simvastatin can degrade CRP,decrease the content of macrophage in aorta wall,refrain artery endomenbrane hyperplasy and the progression of atherosclerosis.Inhibitory effects of their combination on the Progression of Atherosclerosis is better.