大鼠膝关节软骨与不同强度跑台运动的影响

Effects of treadmill running exercise with different intensity on articular cartilage in rats

背景:适量的运动是维持正常关节组织形态结构及生理功能的必要条件,过度运动或制动均可导致关节软骨退变。目的:观察不同强度跑台运动对大鼠膝关节软骨的影响。方法:将18只雄性成年Wistar大鼠随机分安静组、低强度运动组、高强度运动组。6周后ELISA法测定血清基质金属蛋白酶3水平,并行蕃红-O染色、基质金属蛋白酶3与Ⅱ型胶原免疫组织化学染色及Mankin评分,反转录聚合酶链反应检测软骨基质金属蛋白酶3的mRNA表达。结果与结论:高强度运动组Mankin评分、血清及软骨中基质金属蛋白酶3表达均显著高于安静组与低强度运动组(P<0.05),基质糖氨多糖及Ⅱ型胶原含量均显著低于安静组与低强度运动组(P<0.05);低强度运动组与安静组差异无显著性意义。说明高强度运动可造成大鼠膝关节软骨退行性变,且软骨运动性损伤可能与基质金属蛋白酶3表达增强有关。

BACKGROUND： Moderate activities are necessary to maintain the normal structure, histological morphology and physiological function of joints. Excessive exercise and immobility lead to articular cartilage degeneration. OBJECTIVE： To explore the effects of treadmill running exercise with different intensity on articular cartilage of rat knee joints. METHODS： A total of 18 male adult Wistar rats were randomly assigned into three groups： sedentary group, low intensity exercise group and high intensity exercise group. Serum samples were collected to measure matrix metalloproteinase 3 content using enzyme linked immunosorbent assay. In addition, cartilage characteristics were observed by safranin-O staining. Matrix metalloproteinase 3 and type Ⅱ collagen were stained by immunohistochemical staining, and were evaluated by Mankin’s histological grading system. The mRNA expression of matrix metalloproteinase 3 in cartilage was detected by reverse transcription-PCR. RESULTS AND CONCLUSION： Compared with sedentary group and low intensity exercise group, significant differences were found in high intensity exercise group in terms of Mankin’s score, matrix metalloproteinase 3 concentrations in the serum and cartilage （P 〈 0.05）. The contents of matrix glycosaminoglycan and type Ⅱ collagen in high intensity exercise group were significantly lower than those in the sedentary group and low intensity exercise group （P 〈 0.05）. There was no significant difference between sedentary group and low intensity exercise group. These results indicate that high intensity exercise can lead to articular cartilage degeneration in rat knees, and exercise-induced cartilage injury may be related to the increasing expression of matrix metalloproteinase 3.