高脂饮食兔膝关节软骨的变化

Effect of high-fat diet on rabbit knee articular cartilage

背景:血清胆固醇水平增高与人群中骨关节病发病率增高呈正相关,而对于高脂饮食是否参与关节软骨退变过程从而诱发骨关节炎,目前尚不清楚。目的:观察经高脂喂养后新西兰兔膝关节软骨形态学改变,探索饮食在关节软骨退变过程中的作用。方法:将新西兰兔40只随机分为2组:对照组饲以基础饲料,高脂组饲以高脂饲料(20%猪油混合80%的基础饲料)。每4周末抽取空腹血样,测三酰甘油、总胆固醇水平。饲养28周后,取兔膝关节行大体观察后,取股骨髁部软骨行扫描电镜观察。结果与结论:与对照组相比,高脂组血清三酰甘油、总胆固醇水平均显著升高(P<0.05)。扫描电镜观察发现,高脂组髁软骨表面粗糙,陷凹变浅,排列杂乱,形态不规则,大小不均,软骨表面呈局灶性剥脱改变,排列变得不规整,孔隙不均匀,软骨表面出现断裂空洞。进一步放大倍数观察可见软骨表面小山峰样结构变浅、变平,孔隙基本消失。结果证实,长期高脂饮食可诱发和加重软骨损伤,提示其可能参与了骨关节炎的发生发展。

BACKGROUND：The increase of serum cholesterol levels is positively correlated with the increasing incidence of osteoarthritis. Little is known about the role of high-fat diet in the degeneration of articular cartilage and induced arthritis. OBJECTIVE：To observe the morphology change of the articular cartilage of New Zealand rabbits after high-fat diet, and explore the role of food in the articular cartilage degeneration. METHODS：Forty New Zealand white rabbits were randomly divided into two groups. In control group, rabbits were fed with basal diet. In high-fat diet group, rabbits were fed with high-fat diet （20%lard and 80%basal diet）. Fasting blood samples was taken every 4 weeks, to detect the triglyceride and total cholesterol levels. After rabbit were fed for 28 weeks, the knee joint was grossly observed and the femoral condyle cartilage was scanned by scanning electron microscope. RESULTS AND CONCLUSION：Compared with the control group, the triglyceride and total cholesterol levels were significantly increased in the high fat group （P〈0.05）. Under scanning electron microscope, the high-fat group showed rough surface of condylar cartilage, shal ow pouch, messy arrangement, irregular shape and uneven size. The surface of cartilage exhibited focal denudation, irregular arrangement, uneven porosity and fractured cavity. Under higher magnification, smal mountain-like structure of cartilage surface became shal ow and flattened, the pores disappeared. Long-term high-fat diet may induce and aggravate cartilage damage, suggesting it may be involved in the pathogenesis of osteoarthritis.