Gustafson S B, Trotter G W, Norrdin R W, Wrigley R H, Lamar C
Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins 80523.
Am J Vet Res. 1992 Jul;53(7):1193-202.
Three doses of sodium monoiodoacetate (MIA) were used to induce degenerative changes in articular cartilage in middle carpal joints of horses. Twelve young (2- to 5-year-old) horses, free of lameness, were randomly allotted to 3 groups. One middle carpal joint of each horse was injected with 0.9% NaCl solution (control joint). The contralateral middle carpal joint was injected with 0.09 mg of MIA/kg of body weight (group 1); 0.12 mg/kg (group 2); or 0.16 mg/kg (group 3). After MIA administration, horses were allowed ad libitum exercise in a 2-acre paddock for 12 weeks. At the end of the study, gross and microscopic tissue changes were evaluated and biochemical analyses of articular cartilage were done. Grossly, diffuse partial-thickness articular cartilage lesions were observed in group-2 (n = 2) and group-3 (n = 4) horses, but not in group-1 horses. Articular cartilage uronic acid content was significantly (P less than 0.03) decreased in all MIA-injected joints, compared with controls. Articular cartilage matrix staining with safranin-O was decreased in 3 of 4 MIA-injected joints of group-1 horses and in all MIA-injected joints of group-2 and group-3 horses, compared with controls (P less than 0.06). Microscopic degenerative changes in articular cartilage were not significantly different between MIA-injected and control joints in group-1 horses, but were increased (P less than 0.06) in all MIA-injected joints of group-2 and group-3 horses, compared with controls. Qualitatively, decreased matrix staining and degenerative changes were more severe in group-3 horses. On the basis of articular cartilage gross and microscopic changes, as well as biochemical changes, 0.12 mg of MIA/kg injected intra-articularly was determined to induce moderate degrees of articular cartilage degeneration. This model of chemically induced articular cartilage injury could be useful for evaluating treatment effects of anti-arthritic drugs in horses.
使用三剂单碘乙酸钠（MIA）诱导马腕中关节的关节软骨发生退行性变化。12匹无跛行的年轻（2至5岁）马被随机分为3组。每匹马的一个腕中关节注射0.9%氯化钠溶液（对照关节）。对侧腕中关节注射0.09 mg MIA/kg体重（第1组）；0.12 mg/kg（第2组）；或0.16 mg/kg（第3组）。给予MIA后，让马在2英亩的围场中自由运动12周。在研究结束时，评估大体和微观组织变化，并对关节软骨进行生化分析。大体上，在第2组（n = 2）和第3组（n = 4）的马中观察到弥漫性部分厚度关节软骨损伤，但在第1组的马中未观察到。与对照组相比，所有注射MIA的关节中关节软骨糖醛酸含量均显著降低（P < 0.03）。与对照组相比，第1组注射MIA的4个关节中有3个以及第2组和第3组所有注射MIA的关节中，番红O对关节软骨基质的染色减少（P < 0.06）。第1组注射MIA的关节与对照关节之间关节软骨的微观退行性变化无显著差异，但与对照组相比，第2组和第3组所有注射MIA的关节中微观退行性变化增加（P < 0.06）。定性地说，第3组马的基质染色减少和退行性变化更严重。根据关节软骨的大体和微观变化以及生化变化，确定关节内注射0.12 mg MIA/kg可诱导中度关节软骨退变。这种化学诱导的关节软骨损伤模型可用于评估抗关节炎药物对马的治疗效果。
