ABSTRACT

Purpose: In experimental models of equine joint-injury and osteoarthritis synovial fluid (SF) composition (proteoglycan-4, hyaluronan) can vary, along with changes to SF mechanical function (lubrication, viscosity). The study hypotheses were a) clinical equine joint-injury and disease results in altered SF composition and diminished mechanical function, and b) serum composition (proteoglycan-4 or hyaluronan) changes concurrently. The objectives were to characterize composition (proteoglycan-4, hyaluronan), and function of SF and serum from normal horses compared to clinical groups: osteoarthritis, acute-joint-injury, and osteochondrosis.

Materials and Methods: Equine samples of SF (from various joints) and blood were collected at the point-of-care. Proteoglycan-4 concentrations were measured by amplified-luminescence-proximity-assay and enzyme-linked-immunosorbent-assay in SF and serum, respectively. Molecular-weight of hyaluronan was characterized by agarose-gel-electrophoresis, and concentrations were measured by enzyme-linked-immunosorbent-assay kit. Biomechanical function of SF was characterized by an in vitro cartilage-on-cartilage friction test, and viscosity test.

Results: SF proteoglycan-4 concentration increased in acute-joint-injury (1185 ± 276 versus normal 205 ± 106 µg/mL, µ± SEM, p < 0.01), with increased percentage of lower molecular-weight hyaluronan in acute-joint-injury and osteochondrosis. SF and serum proteoglycan-4 concentrations were correlated in normal horses (r² = 0.85, p < 0.05), but not in clinical groups. Cartilage-lubricating ability was unchanged, although steady-shear viscosity of acute-joint-injury SF decreased from normal.

Conclusion: Composition of SF from cases of equine acute-joint-injury changed; both proteoglycan-4 concentration and hyaluronan molecular-weight were altered, with decreased SF viscosity, but no associated changes to serum. Serum proteoglycan-4 and hyaluronan concentrations alone may not be useful biomarkers for equine joint-injury or disease.

摘要

目的：在马关节损伤和骨关节炎的实验模型中，滑液 (SF) 成分（蛋白聚糖 4、透明质酸）会随着 SF 机械功能（润滑、粘度）的变化而变化。研究假设是 a) 临床马关节损伤和疾病导致 SF 成分改变和机械功能降低，以及 b) 血清成分（蛋白聚糖 4 或透明质酸）同时发生变化。目的是描述与临床组相比，正常马的 SF 和血清的组成（蛋白多糖 4、透明质酸）和功能：骨关节炎、急性关节损伤和骨软骨病。

材料和方法：在护理点收集马 SF（来自不同关节）和血液样本。分别通过 SF 和血清中的放大发光接近测定法和酶联免疫吸附测定法测量 Proteoglycan-4 浓度。通过琼脂糖凝胶电泳表征透明质酸的分子量，并通过酶联免疫吸附测定试剂盒测量浓度。SF 的生物力学功能通过体外软骨-软骨摩擦试验和粘度试验来表征。

结果: SF proteoglycan-4 浓度在急性关节损伤中增加（1185 ± 276 与正常 205 ± 106 µg/mL, µ± SEM, p < 0.01），急性关节损伤中低分子量透明质酸的百分比增加损伤和骨软骨病。SF 和血清蛋白多糖 4 浓度在正常马中相关（r ²  = 0.85，p < 0.05），但在临床组中不相关。软骨润滑能力没有改变，尽管急性关节损伤 SF 的稳定剪切粘度比正常值有所下降。

结论：马急性关节损伤病例的SF成分发生了变化；蛋白多糖 4 浓度和透明质酸分子量都发生了改变，SF 粘度降低，但血清没有相关变化。单独的血清蛋白多糖 4 和透明质酸浓度可能不是马关节损伤或疾病的有用生物标志物。