Endothelial leukocyte transmigration in endoglin heterozygous mice treated with inflammatory stimuli. (A-B) Total leukocyte endothelial transmigration was monitored in carrageenan-treated and untreated Eng^+/+ and Eng^+/− mice. Subpopulations of leukocytes were monitored in the peritoneal fluid (A). Total leukocyte count (TLC) was measured in peritoneal fluid and blood (B). Data are the average of 3 experiments with 5 mice per experiment and group. *P < .05, respect to untreated animals; δP < .05, respect to carrageenan-treated Eng^+/+ mice; #P < .05, respect to untreated Eng^+/+ mice. (C-D). Transmigration in endoglin heterozygous mice injected with LPS. Myeloperoxidase (MPO) activity (C) and immunohistochemistry for the macrophage marker CD68 (D) in lung 4 hours after induction of systemic inflammation with LPS (25 mg/kg body weight) in Eng^+/+ and Eng^+/− mice. (C) Enzymatic activity values are represented as MPO/min/10 μg protein in lung tissues from untreated (white bars) or LPS-treated (green bars, n = 5) animals (white bars, n = 5). Values are expressed as mean ± SEM of 4 experiments with 5 mice per experiment and group. *P < .02, untreated versus LPS-treated; δP < .05, respect to LPS-treated Eng^+/+ mice. (D) Immunofluorescence staining with anti-CD68 in lung sections (3 μm) from the same mice as in panel C). Representative photographs are shown. Magnification, 400×.