Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1999: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1998: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1997: ¥1,200,000 (Direct Cost: ¥1,200,000)
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Research Abstract |
The role of neurogenic inflammation in pathogenesis of synovitis in osteoarthritic knees was investigated. Synovial tissue samples were obtained from the medial, lateral synovium and suprapatellar pouch in medial compartmental osteoarthritic knees and localization of neural elements in synovium was immunohistochemically studies using antibodies of substance P, calcitonine gene-related peptide, neuropeptide Y and vasoactive intestinal peptide. Substance P positive free nerve endings were more frequently found in the medial region, which showed more dendritic morphologic features than did those in the lateral and suprapatellar region. Immunohistochemical study of characterization of infiltrated cells in the synovium showed that CD68 positive cells were more abundant in the lining cell laver, and CD4 and HLA-DR positive cells were more often found in the sublsynovial tissue in the medial synovium than those in the lateral, and degenerative cartilage fragments were more entrapped in the medial lining cells. In vitro experiment, T cells exposed to substance P increased in number, whose proliferation was caused by production of IL-2. In animal model of ostoarthritis induced by ACL laceration and partial medial menicectomy, cutting off the femoral nerve brought about more rapid advancement of cartilage degeneration. Overall results indicated that neurogenic inflammation and immunoresponce of T cell-macrophage interaction may be the main cause of synovitis in osteoarthritic knees. Accordingly, in the medical treatment for osteoarthritis of the knee, development of drugs that compete to action of substance P and neurologically keep a homeostasis of a knee joint should be necessitated.
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