Abstract: Objective: atherosclerosis model in rabbits were established by feeding high-fat diets. to observed the effects on protect the vascular endothelium of hirudo and atorvastatin. Methods: feeding group A (normal diets) and model group (high-fat diets) 9 weeks, after the successful establishment of models divided the alive rabbits into four groups: rabbits in group B were fed with high-fat diets; rabbits in group C were fed with high-fat diets which mixed hirudo medicinalis powder 0.5 g/Kg/d; rabbits in group D were fed with high-fat diets which mixed hirudo medicinalis powder 1.5g/Kg/d; rabbits in group E were fed with high-fat diets which mixed atorvastatin 2.5mg/Kg/d. At the end of 17th week, blood samples were taken and made into serum for testing assay lipid , NO, ET-1, PGF-1-α, TXB2, and CRP. Then all rabbits were sacrificed, and the thoracic aortas of them were taken out. The arteries were embedded in paraffin and cut into transverse sections. They were subjected to the HE-staining which could observe changes of the arteries in morphological. Results: Macroscopic observation：there was no difference of the plaque area between group D and group E, and both smaller than group B(p＜0.05). The TC, LDL, TXB2, ET-1 and CRP of group D higher than group B, while the NO and PGF-1-α lower than group B. The TC, LDL and NO of group D higher than group B while the ET-1 lower than group B. All the differences had statistical significance. Discussion: Hirudo has a remarkable effect on protect the vascular endothelium . Its mechanism is related to increasing NO and PGI2, while decreasing TXB2 and ET-1.

Key words: atherosclerosis HIRUDINcholesterol cholesterol, LDL Nitric Oxidethromboxane B2disease models, animalatorvastatin, 疾病模型