title: Early intraarticular injection of hyaluronic acid attenuates osteoarthritis progression in anterior cruciate ligament-transected rats.
abstract: METHODS
  Hyaluronic acid (HA) is widely used to relieve the symptoms of osteoarthritis (OA). An association of reduction of glutamate content with the synovial fluid of OA rats was reported previously.
  
  
  METHODS
  Anterior cruciate ligament transaction (ACLT) was performed on one knee in male Wistar rats, the other knee was assigned to sham control and HA or saline was injected intraarticularly into the ACLT knee from week 3 to week 7. Knee dialysate was collected for amino acid measurement at week 20. Morphology and histopathology of the femoral medial condyles and synovium were examined and evaluated using Mankin and synovitis scores.
  
  
  RESULTS
  HA injection provided better cartilage (3.38 ± 0.03 vs. 5.45 ± 0.0.02) and synovial condition (3 ± 0.02 vs. 6.03 ± 0.02) than saline controls. Moreover, HA injection reduced the concentration of glutamates in knee dialysates compared to saline controls (1.11 ± 0.14-folds and 2.21 ± 0.19-folds of the sham-operated knee, respectively). Cystine/glutamate antiporter system [Formula: see text] expression was significantly downregulated in the saline group, but not in the HA group (0.32 ± 0.08-folds and 0.71 ± 0.10-folds of the sham-operated knee, respectively).
  
  
  CONCLUSIONS
  Early intraarticular injection of HA attenuates the progression of cartilage destruction in the ACLT knee, and the downregulation of the cystine/glutamate antiporter system [Formula: see text] was accompanied by the progression of OA.
authors.affiliation: Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Wei-Yuan
authors.initials: WY
authors.lastname: Tsai
authors.forename: Jia-Lin
authors.initials: JL
authors.lastname: Wu
authors.forename: Chih-Chung
authors.initials: CC
authors.lastname: Liu
authors.forename: Chen-Hwan
authors.initials: CH
authors.lastname: Cherng
authors.forename: Ru-Yin
authors.initials: RY
authors.lastname: Tsai
authors.forename: Yen-Hsuan
authors.initials: YH
authors.lastname: Jean
authors.forename: Chih-Shung
authors.initials: CS
authors.lastname: Wong
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D027182:Amino Acid Transport System y+ / Q000235:genetics / Q000378:metabolism; D000818:Animals; D016118:Anterior Cruciate Ligament / Q000473:pathology; D000070598:Anterior Cruciate Ligament Injuries; D002358:Cartilage, Articular / Q000293:injuries* / Q000473:pathology; D004195:Disease Models, Animal; D018450:Disease Progression; D004334:Drug Administration Schedule; D005786:Gene Expression Regulation; D006820:Hyaluronic Acid / Q000008:administration & dosage*; D007270:Injections, Intra-Articular; D008297:Male; D020370:Osteoarthritis, Knee / Q000175:diagnosis / Q000517:prevention & control*; D051381:Rats; D017208:Rats, Wistar; D013264:Stifle / Q000293:injuries / Q000473:pathology; D013997:Time Factors
chemical_list: D000276:Adjuvants, Immunologic; D027182:Amino Acid Transport System y+; D006820:Hyaluronic Acid