Figure 2.

Effects of mast cells and plasmacytoma cells on angiogenesis in vivo. BALB/c nu/nu mice (3–5 mice per group) were inoculated s.c. with Matrigel (0.5 ml) in conjunction with BMMCs (0.5 × 10⁶), TEPC2027 plasmacytoma cells (0.5 × 10⁶), or BMMCs plus TEPC2027 cells (0.5 × 10⁶ each). Matrigel plugs, removed after 7 days, were processed for histology. (A) Top row: Representative histological images of Matrigel plugs stained with Masson’s trichrome. Bottom row: Representative histological images of Matrigel plugs immunostained for κ light chain. Original magnification, ×20. (B) Quantitative analysis of neovascularization (top) and plasmacytoma cell infiltration (bottom) in all Matrigel plugs (3–5 plugs per group; 1 plug per animal). Neovascularization was measured as the areas occupied by vascular structures and is expressed as the mean surface area (± SD of measurements from individual plugs in each group) occupied by vascular structures in each group. Plasmacytoma cell infiltration was measured by counting plasmacytoma cells present in each plug section and is expressed as the mean cell number (± SD of measurements in individual plugs from each group). (C) Consecutive sections containing BMMCs plus TEPC2027 cells were double-stained with toluidine blue and Tie-2/Fc or control Fc. Mast cells, purple due to toluidine blue and brown due to Tie-2/Fc (but not control Fc), localize in the proximity of a vessel. Original magnification, ×40.