Figure 5

Histological analysis of infrapatellar fat pad harvested from rabbit knees 21 days after arthritis onset. Rabbits with antigen-induced arthritis (AIA) were treated with daily injections of adrenomedullin (AM) or saline (control) into the knee joint spaces for 20 days. The infrapatellar fat pads were harvested from rabbit knees 21 days after arthritis onset. The tissues were sectioned longitudinally perpendicular to the patella ligament in the middle of the tissue, and were stained with H & E. (a), (b), (c) AIA rabbit knee was treated with daily intra-articular injections of 3 μg AM for 20 days. (a) Low-magnification image (×100). (b), (c) High-magnification images (×400) of the superficial portion and the deep portion of (a), respectively. (d), (e), (f) The contralateral knee of (a), (b) and (c) was treated with daily intra-articular injections of saline for 20 days. (d) Low-magnification image (×100). (e), (f) High-magnification images (×400) of the superficial portion and the deep portion of (d), respectively. Arrows indicate inflammatory cells. Bar = 50 μm.