title: Nutrition and degeneration of articular cartilage.
abstract: OBJECTIVE
  To determine the importance of synovial fluid (SF) or subchondral bone marrow (BM) as nutrition sources in cartilage degeneration.
  
  
  METHODS
  Ninety-five-month-old male rabbits were randomly divided into 5 groups according to sources of nutrition: SFBM-both; BM-only; SF-only; None-SFBM; and Free plug (unrestricted). Nutrition to 4-mm-diameter cylindrical osteochondral plugs created on the trochlea of the distal femurs was obstructed by Polyvinyl Chloride (PVC) cap. Cartilage changes were assessed after 4, 8, and 12 weeks by histology, immunohistochemistry, and real-time PCR.
  
  
  RESULTS
  Cartilage in the BM-only group suffered the greatest damage, followed by the None-SFBM and SF-only groups. Apoptosis was increased in the BM-only and None-SFBM groups compared with others. Cartilage was significantly thinner at all time points in the BM-only and None-SFBM groups when compared with SFBM-both and Free plug, whereas in the SF-only group, this difference occurred after 8 weeks. Compared with SFBM-both and Free plug, expression of collagen II and aggrecan mRNAs in all groups was decreased but MMP-3 increased, respectively.
  
  
  CONCLUSIONS
  Our data indicate that SF-derived nutrition is the dominant source of sustenance for adult cartilage structure and function. Cartilage damage is observed when the only nutrition source is the BM.
authors.affiliation: Department of Orthopaedics, The Second Hospital of Shanxi Medical University, 382 Wuyi Road, Taiyuan, 030001, Shanxi, People's Republic of China.
authors.forename: Yuze
authors.initials: Y
authors.lastname: Wang
authors.forename: Lei
authors.initials: L
authors.lastname: Wei
authors.forename: Lingyuan
authors.initials: L
authors.lastname: Zeng
authors.forename: Dongdong
authors.initials: D
authors.lastname: He
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Wei
mesh_terms: D053674:Aggrecans / Q000235:genetics / Q000378:metabolism; D000704:Analysis of Variance; D000818:Animals; D017209:Apoptosis; D001853:Bone Marrow / Q000378:metabolism*; D002358:Cartilage, Articular / Q000473:pathology*; D019902:Chondrocytes / Q000473:pathology; D024043:Collagen Type II / Q000235:genetics / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D053509:Matrix Metalloproteinase 13 / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011817:Rabbits; D011897:Random Allocation; D060888:Real-Time Polymerase Chain Reaction; D013582:Synovial Fluid / Q000378:metabolism*
chemical_list: D053674:Aggrecans; D024043:Collagen Type II; D012333:RNA, Messenger; D053509:Matrix Metalloproteinase 13