CCR2 inhibition and CCR2KO BMT reduce leukocyte infiltration into the heart following MI. (A) Representative CD68, tryptase, and MPO staining for the infarct zone of hearts from WT C57BL/6 mice that underwent MI surgery followed by administration (i.p.) of 2 mg⋅kg−1⋅d−1 of a CCR2 antagonist or vehicle for 4 d or WT C57BL/6 mice receiving WT, β2ARKO, or CCR2KO BMT animals that underwent MI surgery. Arrowheads indicate positive staining. Insets show higher magnification at 250×. (B–D) Quantification of CD68 (B), tryptase (C), and MPO (D) staining for the infarct zone of 4-d post-MI hearts from Veh- and CCR2 antagonist-treated mice or WT, β2ARKO, and CCR2KO BMT animals. n = 4–8; t test or one-way ANOVA, *P < 0.05 vs. WT BMT or Veh, ‡P < 0.001 vs. Veh BMT. Data are expressed as mean ± SEM.