木瓜蛋白酶诱导大鼠膝早期骨关节炎软骨表面的电镜扫描

背景：木瓜蛋白酶注射建立骨性关节炎动物模型是用于骨关节炎防治研究的常用方法之一。 目的：观察木瓜蛋白酶和L-半胱氨酸混合注射诱导大鼠膝早期骨关节炎进程中扫描电镜下软骨表面形态学变化。 方法：2%木瓜蛋白酶和0.03 mol/L左旋半胱氨酸按2∶1比例混匀，取0.15 mL注射至SD大鼠右膝关节腔诱导骨关节炎模型，左膝注射等量生理盐水为对照组，另取2只4膝不做处理为正常对照组，于注射后第2，4，6周后分别使用扫描电镜观察股骨内侧髁关节软骨表面形态学变化。 结果与结论：正常和对照组可见表面分布较均匀的浅坑。木瓜蛋白酶和L-半胱氨酸混合注射2周后大鼠软骨表面出现凹凸不平，皱缩扭曲变形；4周表面变薄，局部出现小裂纹；6周出现深大裂纹，软骨缺损。提示2%木瓜蛋白酶和0.03 mol/L左旋半胱氨酸混合注射诱导的早期骨关节炎模型的时间节点可以定在4-6周。

Cartilage surface of early osteoarthritis in rats induced by papain under scanning electron microscope

BACKGROUND： Osteoarthritis animal models induced by papain are commonly used for studying osteoarthritis.
OBJECTIVE： To observe the morphology of articular cartilage surface during early osteoarthritis process in rats induced by papain and L-cysteine under scanning electron microscope.
METHODS： The right knees of Sprague-Dawley rats were given 0.15 mL mixed solution of 2% papain and 0.03 mol/L L-cysteine in the ratio of 2：1. The left knees were given injections of 0.15 mL 0.9% NaCl, as the control group. Another two rats （four knees） maintained untreated, as the normal control group. All the rats were observed with scanning electron microscope at 2, 4, 6 weeks after injection, to explore the surface morphology of medial condyle of femur.
RESULTS AND CONCLUSION： The condyles of normal and control groups revealed numerous shallow pits on the surface of articular cartilage. At 2 weeks after injection, the surfaces of condyles were unsmooth, presenting the shrinkage and distortion. The thinner articular cartilage and local tiny cracks were seen at 4 weeks. The deep and great cracks and cartilage defect were observed on the surface of cartilage at 6 weeks. The time of 4- 6 weeks is a reference point for establishing early osteoarthritis model in rats through injections of 2% papain and 0.03 mol/L L-cysteine.