Immunohistochemical demonstration of the presence of inflammatory cells in muscles of WT and Plg-deficient mice after glycerol-induced injury.

Detection of neutrophils (Gr-1⁺) (A), macrophages (Mac-1⁺) (B), and T cells (T11⁺) (C) in transverse sections of control and injured skeletal muscles of WT and Plg-deficient mice at the indicated times AI. (D) Quantitative analysis of Gr-1⁺, Mac-1⁺, and T11⁺ cells in regenerating muscles of WT and Plg-deficient mice. Gr-1⁺, Mac-1⁺, and T11⁺ cells were counted in 10 random fields per section, and data from 12 sections per muscle were pooled. The mean values for both limbs were to provide a mean value for each animal (3 animals were studied at each time point). Histograms show the percentage of reduction of Mac-1⁺ and T11⁺ cells (50% and 30%, respectively) in Plg^−/− mice (gray bars) with respect to WT mice (black bars); statistical significant (P < .05) is denoted. Gr-1–expressing cells were maximal 12 hours AI in both WT and Plg-deficient mice. Mac-1– and T11-expressing cells increased 2 days AI in muscle of WT and Plg-deficient mice; however, the number of Mac-1⁺ and T11⁺ cells was lower in Plg^−/− mouse muscle. Original magnifications × 400.