title: [Quantification of papain-induced rat osteoarthritis in relation to time with the Mankin score].
abstract: OBJECTIVE
  The aim of this study was to evaluate structural changes in relation to time with the use of the Mankin scoring system in papain-induced rat osteoarthritis.
  
  
  METHODS
  Osteoarthritis was induced in 21 male Wistar rats by injecting an admixture of 4% papain (10 microl) and its activator 0.03 M cycteine (10 microl) into the right knee joints on the first, fourth, and seventh days. The same volume of sterile saline solution was injected into the left knees as controls. The rats were assigned to three groups equal in number and were sacrificed under high-dose ether anesthesia after one, two, and four weeks of the last papain injection, respectively. The study and control knee joints were removed and histologic changes in cartilage structure were assessed and quantified with the modified Mankin scoring system.
  
  
  RESULTS
  Histologically, all papain injected knees exhibited irregularity and fibrillation in the superficial layer, decreased cell count and multilayering in transitional and radial zones, and no pannus formation. The modified Mankin scores were significantly higher compared to the control knees in all the groups (p<0.05), being 4.3+/-0.9, 6.9+/-1.3, and 10.4+/-1.9 in diseased knees, and 2.7+/-0.5, 4.0+/-0.8, and 4.4+/-1.0 in the control knees after one, two, and four weeks of the last papain injection, respectively. There was a significant difference between the Mankin scores of the rats sacrificed after one and four weeks of the last papain injection (p=0.0471).
  
  
  CONCLUSIONS
  Findings observed after four weeks of papain injection seem to be consistent with early osteoarthritic changes. Our results may provide insight into therapeutic strategies for early osteoarthritis.
authors: Dokuz Eylül Universitesi Tip Fakültesi, Farmakoloji Anabilim Dali.
authors: Nergis
authors: N
authors: Murat
authors: Bahattin
authors: B
authors: Karadam
authors: Sermin
authors: S
authors: Ozkal
authors: Vasfi
authors: V
authors: Karatosun
authors: Sedef
authors: S
authors: Gidener
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000187:drug effects; D004195:Disease Models, Animal; D008297:Male; D020370:Osteoarthritis, Knee / Q000139:chemically induced / Q000503:physiopathology*; D010206:Papain / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012720:Severity of Illness Index
chemical_list: D010206:Papain