Fig. 1From: Role of vasoactive intestinal peptide in osteoarthritisNegative role of VIP in osteoarthritis pathogenesis. The expression of VIP is down-regulated in synovial fluid of OA and down-regulation of VIP stimulates the production of pro-inflammatory cytokines that might contribute to the pathogenesis of OA by developing pain, joint inflammation and cartilage degradation [16, 25, 33]Back to article page