Rehabilitation Science Program, Department of Health Science, Graduate School, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea.
Transdisciplinary Major in Learning Health Systems, Department of Healthcare Sciences, Graduate School, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea.
Tissue Eng Regen Med. 2023 Jun;20(3):435-446. doi: 10.1007/s13770-023-00520-5. Epub 2023 Feb 21.
This study aimed to identify pain-related behavior and pathological characteristics of the knee joint in rats with monosodium iodoacetate (MIA)-induced osteoarthritis (OA).
Knee joint inflammation was induced by intra-articular injection of MIA (4 mg/50 µL, n = 14) in 6-week-old male rats. Knee joint diameter, weight-bearing percentage on the hind limb during walking, the knee bending score, and paw withdrawal to mechanical stimuli were measured to evaluate edema and pain-related behavior for 28 d after MIA injection. Histological changes in the knee joints were evaluated using safranin O fast green staining on days 1, 3, 5, 7, 14, and 28 after OA induction (n = 3, respectively). Changes in bone structure and bone mineral density (BMD) were examined 14 and 28 d after OA (n = 3, respectively) using micro-computed tomography (CT).
The knee joint diameter and knee bending scores of the ipsilateral joint significantly increased 1 d after MIA injection, and the increased knee joint diameter and knee bending score persisted for 28 d. Weight-bearing during walking and paw withdrawal threshold (PWT) decreased from 1 and 5 d, respectively, and were maintained up to 28 d after MIA. Cartilage destruction started on day 1, and Mankin scores for bone destruction significantly increased for 14 d, as shown by micro-CT imaging.
The present study demonstrated that histopathological structural changes in the knee joint due to inflammation started soon after MIA injection, which induced OA pain from inflammation-related acute pain to spontaneous and evoked associated chronic pain.
本研究旨在确定碘乙酸单钠（MIA）诱导的骨关节炎（OA）大鼠膝关节相关疼痛行为和病理特征。
通过向 6 周龄雄性大鼠关节内注射 MIA（4mg/50μL，n=14）诱导膝关节炎症。在 MIA 注射后 28 天内，通过测量膝关节直径、行走时后肢负重百分比、膝关节弯曲评分和对机械刺激的足退缩来评估肿胀和与疼痛相关的行为。在 OA 诱导后第 1、3、5、7、14 和 28 天（分别为 n=3），使用番红 O 快绿染色评估膝关节的组织学变化。在 OA 后 14 和 28 天（分别为 n=3），使用微计算机断层扫描（CT）检查骨结构和骨密度（BMD）的变化。
MIA 注射后 1 天，患侧膝关节直径和膝关节弯曲评分显著增加，且增加的膝关节直径和膝关节弯曲评分持续 28 天。行走时的负重和足退缩阈值（PWT）分别从第 1 天和第 5 天开始下降，并持续到 MIA 后 28 天。软骨破坏始于第 1 天，Mankin 评分显示骨破坏在 14 天内显著增加，微 CT 成像也证实了这一点。
本研究表明，由于炎症引起的膝关节组织学结构变化在 MIA 注射后很快发生，导致 OA 疼痛从炎症相关的急性疼痛转变为自发性和诱发的慢性疼痛。
