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Updated: Jun 13, 2025
Osteoarthritis Pain Model Induced by Intra-Articular Injection of Mono-Iodoacetate in Rats
Published on: May 20, 2020
Time- and dose-related pathological changes in knee osteoarthritis rat model induced by monosodium iodoacetate
Wei Pu1,2,3, Qi Liu1,2,3, Shuyan Xue1
1Third Clinical College, Shanxi University of Chinese Medicine, Jinzhong, China.
Abstract:
Knee osteoarthritis (KOA) is a chronic degenerative disease. Monosodium iodoacetate (MIA) induction is the most commonly used therapeutic effect evaluation and mechanism of action research model; we observed a lack of standardization and uniformity in current model building methods, which led us to conduct this study.
Background:
The aim was to investigate the time- and dose-related changes in the behavioral and pathological characteristics in the MIA-induced KOA model rat.
Methods:
MIA (40, 50, and 60 mg/mL) was injected into the left joint of male Sprague-Dawley rats. After 2 weeks, the changes in the KOA rat model were observed by behavioral evaluation, imaging-level evaluation, and histological-level evaluation. The changes were also compared after 40-mg/mL MIA injection for 2 and 6 weeks.
Results:
MIA-induced bone surface defects, osteophyte hyperplasia around the articular rim, increased subchondral bone density, thinning of the sparse trabecular bone, structural disorder, and local clustering were observed. The degree of injury gradually increased with the increase in MIA concentration. After 6 weeks, subchondral bone density and sparse trabecular bone increased in the KOA model.
Conclusions:
The severity of the model also increased significantly with the changes in dose and time. In dose-dependent experiments, this study revealed that 40 mg/mL was the optimal dose to induce significant pathological changes without causing undue discomfort or death in animals. This dose may induce pathological changes stably and is suitable for long-term observation.
Insights
This study optimized the monosodium iodoacetate (MIA) rat model for knee osteoarthritis (KOA) research. A 40 mg/mL dose of MIA is recommended for stable, long-term KOA modeling with minimal animal distress.
Area of Science:
- Orthopedics and Sports Medicine
- Preclinical Research Models
- Pharmacology and Toxicology
Background:
- Knee osteoarthritis (KOA) is a prevalent chronic degenerative joint disease.
- The monosodium iodoacetate (MIA) injection model is widely used for KOA research.
- Current MIA model induction methods lack standardization, necessitating optimization.
Purpose of the Study:
- To investigate the time- and dose-dependent effects of MIA on KOA development in rats.
- To establish standardized parameters for the MIA-induced KOA rat model.
- To identify optimal MIA concentration and duration for reliable KOA modeling.
Main Methods:
- Male Sprague-Dawley rats received intra-articular MIA injections (40, 50, 60 mg/mL).
- KOA model characteristics were assessed via behavioral, imaging, and histological evaluations at 2 weeks.
- Comparisons were made between 2 and 6 weeks post-injection with 40 mg/mL MIA.
Main Results:
- MIA induced dose-dependent pathological changes including bone defects, osteophytes, and altered subchondral bone density.
- Increased MIA concentration correlated with greater injury severity.
- Longer observation (6 weeks) showed increased subchondral bone density and sparse trabecular bone in the KOA model.
Conclusions:
- MIA dose and time significantly influence KOA model severity.
- 40 mg/mL MIA is identified as the optimal dose for inducing significant pathological changes without causing excessive animal distress or mortality.
- This optimized dose supports stable induction of KOA pathology suitable for long-term studies.
