title: Monoiodoacetic acid induces arthritis and synovitis in rats in a dose- and time-dependent manner: proposed model-specific scoring systems.
abstract: In a rat monoiodoacetic acid (MIA)-induced arthritis model, the amount of MIA commonly used was too high, resulting in rapid bone destruction. We examined the effect of MIA concentrations on articular cartilage and infrapatellar fat pad (IFP). We also established an original system for "macroscopic cartilage and bone score" and "IFP inflammation score" specific to the rat MIA-induced arthritis model.
  
  
  
  Male Wistar rats received a single intra-articular injection of MIA in the knee. The amount of MIA was 0.1, 0.2, 0.5, and 1 mg respectively. Articular cartilage was evaluated at 2-12 weeks. IFP was also observed at 3-14 days.
  
  
  
  Macroscopically, low MIA doses induced punctate depressions on the cartilage surface, and cartilage erosion proceeded slowly over 12 weeks, while higher MIA doses already induced cartilage erosion at 2 weeks, followed by bone destruction. MIA macroscopic cartilage and bone score, OARSI histological score, and Mankin score increased in a dose- and time-dependent manner. The IFP inflammation score peaked at 5 days in low dose groups, then decreased, while in high dose groups, the IFP score continued to increase over 14 days due to IFP fibrosis.
  
  
  
  Punctate depressions, cartilage erosion, and bone destruction were observed in the MIA-induced arthritis model. The macroscopic cartilage and bone scoring enabled the quantification of cartilage degeneration and demonstrated that MIA-induced arthritis progressed in a dose- and time-dependent manner. IFP inflammation scores revealed that 0.2 mg MIA induced reversible synovitis, while 1 mg MIA induced fibrosis of the IFP body.
authors.affiliation: Department of Joint Surgery and Sports Medicine, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan. Electronic address: udo.orj@tmd.ac.jp.
authors.forename: M
authors.initials: M
authors.lastname: Udo
authors.affiliation: Department of Joint Surgery and Sports Medicine, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan. Electronic address: muneta.orj@tmd.ac.jp.
authors.forename: T
authors.initials: T
authors.lastname: Muneta
authors.affiliation: Department of Cartilage Regeneration, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan. Electronic address: tsuji.orj@tmd.ac.jp.
authors.forename: K
authors.initials: K
authors.lastname: Tsuji
authors.affiliation: Center for Stem Cell and Regenerative Medicine, Tokyo Medical and Dental University, Tokyo, Japan. Electronic address: ozeorj@tmd.ac.jp.
authors.forename: N
authors.initials: N
authors.lastname: Ozeki
authors.affiliation: Department of Joint Surgery and Sports Medicine, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan. Electronic address: ynakagawa.orj@tmd.ac.jp.
authors.forename: Y
authors.initials: Y
authors.lastname: Nakagawa
authors.affiliation: Department of Joint Surgery and Sports Medicine, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan. Electronic address: ohara.orj@tmd.ac.jp.
authors.forename: T
authors.initials: T
authors.lastname: Ohara
authors.affiliation: Department of Joint Surgery and Sports Medicine, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan. Electronic address: saito.orj@tmd.ac.jp.
authors.forename: R
authors.initials: R
authors.lastname: Saito
authors.affiliation: Department of Joint Surgery and Sports Medicine, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan. Electronic address: yanagisawa.orj@tmd.ac.jp.
authors.forename: K
authors.initials: K
authors.lastname: Yanagisawa
authors.affiliation: Department of Joint Surgery and Sports Medicine, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan. Electronic address: koga.orj@tmd.ac.jp.
authors.forename: H
authors.initials: H
authors.lastname: Koga
authors.affiliation: Center for Stem Cell and Regenerative Medicine, Tokyo Medical and Dental University, Tokyo, Japan. Electronic address: sekiya.arm@tmd.ac.jp.
authors.forename: I
authors.initials: I
authors.lastname: Sekiya
mesh_terms: D000818:Animals; D002358:Cartilage, Articular; D007270:Injections, Intra-Articular; D019807:Iodoacetic Acid; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013585:Synovitis
chemical_list: D019807:Iodoacetic Acid
keywords: Cartilage degeneration; Monoiodoacetic acid; Osteoarthritis; Rat; Scoring system; Synovitis