Figure 4

Histological analysis of infrapatellar fat pad harvested from rabbit knees 8 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 7 days. The infrapatellar fat pads were harvested from rabbit knees 8 days after arthritis onset. 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 7 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 7 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.