Fig. 2. Effect of morphine on immunolabeled macrophages in the healing cutaneous wound. Cutaneous wounds were treated twice daily with IntraSite Gel (Smith+Nephew, Hull, United Kingdom) alone or gel infused with 5 mm morphine sulfate (MS). (  A and  B ) Macrosialin immunoreactive cells (  arrows ) in granulation tissue of healing wounds. Fluorescence photomicrographs of (  A ) gel-only and (  B ) morphine-treated wounds were obtained 1 day postwounding. Note a significant decrease in the number of macrophages present in morphine-treated wounds as compared with controls. Scale bar = 100 μm. (  C ) Time course of macrophages present in the periwound area. Data are presented as number of macrosialin immunoreactive cells per unit area (mm²) of histologic sections analyzed. Macrophage infiltration is decreased and delayed in morphine-treated wounds (n = 3 or 4). *  P < 0.05 comparison between morphine and controls treated with gel only (two-way ANOVA, Tukey test).