Papain-induced changes in the guinea pig knee joint with special reference to cartilage healing

Tetsuji Moriizumi, Naoki Yamashita, Yasunori Okada

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)


The repair of articular cartilage following papain injection into the knee joint of the guinea pig was studied by light and electron microscopy, as well as by autoradiography using tritiated thymidine. Papain injection rapidly produced complete degradation of cartilage proteoglycan. Although a number of chondrocytes were also destroyed, the remaining chondrocytes showed mitotic cell division with resultant formation of cell clusters. Such chondrocytic regeneration, however, did not contribute significantly to the repair of cartilage tissue. On the other hand, mesenchymal cells proliferated from the transition zone and extended over the surface of the damaged cartilage. At the peripheral portion of the articular surface, they migrated and differentiated into chondrocytes with the formation of abundant intercellular matrix to produce hyaline cartilage. From these findings, it was apparent that mesenchymal cells in the transition zone were actively engaged in the repair of articular cartilage.

Original languageEnglish
Pages (from-to)461-474
Number of pages14
JournalVirchows Archiv B Cell Pathology Including Molecular Pathology
Issue number1
Publication statusPublished - 1986 Dec
Externally publishedYes


  • Articular cartilage
  • Autoradiography
  • Repair
  • Ultrastructure

ASJC Scopus subject areas

  • Pathology and Forensic Medicine


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