Figure 2. Immunohistochemical micrographs from rat dental pulp (A,B) and compressed PDL (C,D) using antibody that marks CD 43+ cells. Rats were subjected to 10 days of orthodontic tooth movement. Sections A and C are from sympathectomized rats, while B and D are from control rats. (A) Sympathectomized rat showing CD 43+ granulocytes in the dental papilla and periodontal ligament (PDL), while the distal root pulp (P) of the first molar is totally lacking these cells. (B) Section from control rat in the same area. Numerous small CD 43+ cells, both in the distal papilla and dental pulp (open arrow). (C) Mesial surface of distal root from sympathectomized rat showing faintly stained large CD 43+ cells (open arrows) in the compressed PDL near areas of root resorption (arrow). These large immunoreactive cells with membrane staining are probably CD 43+ plasma cells. (D) Section from control rat in the same area as (C). Numerous small CD 43+ cells, mainly granulocytes (open arrows), in the PDL associated with root resorption (arrow). Dn, dentin; H, hyalinized zone; P, pulp; PDL, periodontal ligament. Scale bars, 100 µm. (From Haug et al., 2003; reprinted with permission from Springer)