Fig. 5

Histological appearances of ankles from rats with collagen-induced arthritis treated with AR786 or ibuprofen. Untreated control animal (a) displays normal synovium (S), whereas an ankle from a vehicle-treated arthritic animal (b) displays severe synovitis (S) and moderate cartilage damage (large arrow) with mild pannus (small arrow) and bone resorption (arrowhead). P identifies very severe periosteal bone formation. c Ankle from an arthritic animal treated with AR786 has marked synovitis (S) and mild cartilage damage (large arrow) with minimal pannus (small arrow) and bone resorption. P identifies mild periosteal bone formation. d Ankle from an animal treated with 35 mg/kg ibuprofen has severe inflammation (S) and moderate cartilage damage (large arrow) with mild pannus (small arrow) and bone resorption (arrowhead). P identifies moderate periosteal bone formation. Toluidine blue stain