脂联素与大鼠激素性股骨头坏死的修复

Effects of adiponectin on steroid-induced osteonecrosis of the femoral head in rats

背景:动物实验表明脂联素影响成骨细胞和破骨细胞的增殖和分化,临床研究发现脂联素和骨密度存在着一定的相关性,但具体作用机制尚不清楚。目的:评价髋关节内直接注射重组大鼠脂联素对激素性股骨头缺血性坏死修复的影响。方法:将SD大鼠随机分成4组。空白对照组腹腔注射生理盐水,其余大鼠腹腔注射醋酸泼尼松龙诱导出早期激素性股骨头缺血坏死的模型。随后将低剂量组、高剂量组大鼠右侧髋关节内分别注入1μg、10μg的重组脂联素;生理盐水组注入等量的生理盐水;空白对照组不作任何处理。4周后行X射线平片观察,光镜下观察股骨头坏死和修复的程度。分析骨小梁面积、空骨陷窝数、软骨下骨血管数量,免疫组织化学检测股骨头肿瘤坏死因子α表达情况。结果与结论:空白对照组X射线片无异常发现,生理盐水组、低剂量组显示股骨头密度不均骨小梁模糊;高剂量组股骨头形态和骨密度均正常。大体所见空白对照组骨质硬,生理盐水组骨质明显疏松,低剂量组、高剂量组骨质硬度介于空白对照组、生理盐水组之间。光镜显示空白对照组股骨头软骨、骨小梁、骨细胞、空骨陷窝、毛细血管数及骨髓造血组织均正常,而生理盐水组明显异常,与空白对照组比较差异有显著性意义(P<0.01);高剂量组结果显著优于生理盐水组(P<0.01),低剂量组结果与生理盐水组差异无显著性意义(P>0.05),生理盐水组肿瘤坏死因子α的表达高于其余3组(P<0.01)。结果表明,髋关节内直接注射重组脂联素可促进激素性股骨头缺血性坏死的修复,且具有剂量依赖性。

BACKGROUND： Animal experiment has demonstrated that adiponectin affected proliferation and differentiation of osteoblasts and osteoclasts. The clinical research found that adiponectin has certain correlation to bone density, however, the mechanisms remains poorly understood. OBJECTIVE： To evaluate the effect of direct injection of recombinant rat adiponectin into the hip joint on steroid-induced avascular necrosis of femoral head in rats. METHODS： Sprague Dawley female rats were randomly divided into 4 groups. All rats were established the early steroid-induced avascular necrosis of femoral head models by peritoneal injecting prednisolone acetate except those in the control group, which were received Jsodose physiological saline. Then, the rats in the low dose group and high dose group were injected with 1μg or 10 μg of recombinant adiponectin into the right hip, respectively; those in the saline group were injected with isodose physiological saline. The right femoral head of all rats were examined by X-ray at 4 weeks after the injection. The extent of necrosis and repair were observed under a light microscope. Trabecular bone area, empty bone lacuna rate, vascular number were analyzed and the expression of tumor necrosis factor a （TNF-α） of the femoral head was detected by immunohistochemical method. RESULTS AND CONCLUSION： The results of X-ray examination showed that control group and high dose group were normal, bone density of femoral head was uneven and trabecular bone was fuzzy Jn the saline group and low dose group. Bones of control group were hard, bones of saline group were significantly osteoporosis, bone hardness of low dose group and high dose group were between control group and saline group. Light microscopy showed that trabecular bone, bone lacunae, vascular number of control group were normal, and saline group were significantly abnormal compared with control group （P 〈 0.01）; High dose group was significantly superior to the results of saline group （P 〈 0.01 ）, the differences between low dose group and saline group were not significant （P 〉 0.05）, the expression of TNF-α in the saline group was higher than the other groups （P 〈 0.01）. The results demonstrated that, direct injection of recombinant rat adiponectJn into hip joint can promote the repair of steroid-induced avascular necrosis of femoral head in rats in a dose-dependent correlation.