HRT对去势雌兔动脉血管的影响及血管VEGF表达的研究

INVESTIGATION OF THE INFLUENCE OF HRT OVARIECTOMIZED RABBITS’ ARTERY AND EXPRESSION OF VASCULAR ENDOTHELIAL GROWTH FACTOR(VEGF)

[目的]探讨HRT对去势、高脂饮食雌兔动脉血管的影响及去势雌兔行HRT后血管内皮生长因子(VEGF)表达与动脉粥样硬化病变的关系。[方法]以去势雌性大白兔作为雌激素缺乏模型,喂食高脂饲料复制动脉粥样硬化症,并行HRT后测定兔血脂、观察主动脉血管病理形态学变化及免疫组化sp法检测VEGF。32只兔共分为4组,每组8只,A假手术组,B模型组行双侧卵巢切除术(OVX);C倍美力组,OVX后补充倍美力;D尼尔雌醇+安宫黄体酮组,OVX后补充尼尔雌醇+安宫黄体酮。[结果]各组兔TC、LDL-C、HDL-C指标与正常比较均有不同程度增高。各组与正常兔比较以上指标P﹤0.01;B、C、D与A组比较P﹤0.05;C、D与B组比较P﹥0.05。各组兔胸主动脉血管均见不同程度AS病变,脂质斑块形成;免疫组织化学染色表明各组兔血管内膜斑块区可见不同程度VEGF阳性表达,且AS斑块病变程度与VEGF阳性表达程度呈正相关。[结论]无论应用HRT与否,去势雌兔在进食高脂饲料后均可发生高脂血症,引起AS,VEGF阳性表达,HRT并不能抑制VEGF表达。进而表明在本实验条件下HRT无益于动脉粥样硬化症的预防和治疗。

[Objective] To discuss the influence of HRT on pathological change of rabbits＇ artery, which were ovariectomized and given high cholesterol diet, and the correlation between expression of vascular endothelial growth factor （VEGF） and pathological change of atherosclerosis. [Methods] With ovariectomized female rabbits as the model with female hormone （Estrogen） deficiency, we fed them with high cholesterol diet to simulate atherosclerosis, and then, after HRT, tested the cholesterol level in rabbit blood, observed pathological changes of artery and used SP testing method and immunohistochemical techniques to examine YEGF. 32 rabbits were divided into 4 groups, with 8 in each. Group A was pseudo-surgery group; while Group B was OVX group; Group C was Premarin group （supply Premarin after OVX）; Group D was Nilestriol ＋ Progestational hormone group （supply Nilestriol and Progestational hormone after OVX）. [Results] TC, LDL-C and HDL-C of rabbits in each group were higher than normal values at different levels. All groups above were compared with normal rabbits, P 〈 0.01 in every group. While compared with Group A, P 〈 0.05 in Group B. C and D; While compared with Group B, P 〉 0.05 in Group C and D. In each group, AS pathological changes in thoracic artery and formation of AS plaque were presented at differentiated level, with pseudo-surgery group was the slightest. The resuh of immuno-histochemical coloring demonstrated that different levels of internal epidermis VEGF positive expression can be found in plaque of artery in each group, while the pathological changes of artery plaque was positively related with positive expression of VEGF. [ Conclusion] No matter HRT is applied or not, ovariectomized rabbits will possibly exhibit high cholesterol, causing the positive expression of AS and VEGF. Hence, HRT can not prevent the expression of VEGF. Thus, it is clear that under conditions in this experiment, HRT is not able to prevent or cure atheroselerosis.