BLT1 and BLT2 contribute to HDM-induced eosinophilic airway inflammation. (A, B) Mice were intraperitoneally injected with U75302 or LY255283 1 h before every challenge. We harvested lung tissue 24 h after the last challenge, fixed them in formalin and embedded them in paraffin for section staining. (A) Lung tissue sections were stained with H&E (upper panel) or PAS (lower panel). We measured and scored peribronchial and perivascular lung inflammation or mucus secretion . Data are shown as the mean ± SD (n = 4-5 per group). *P < 0.05, ***P < 0.001 versus each control group. Scale bar, 100 µm. (B) Total immune cells, eosinophils, neutrophils, monocytes and lymphocytes in BALF were obtained using cytospin and stained with Diff-quik. Data are shown as the mean ± SD (n = 4-5 per group). ***P < 0.001 versus each control group. Scale bar, 50 µm.