Fig. 7

The impact of R1B blockade on pulmonary histological lesions due to sepsis. Pulmonary histological analysis 30 h after sham surgery, WT CLP, or WT CLP that received R-954 antagonist. a, c, e, h Hematoxylin–eosin staining. Magnification ×400. Scale: 50 µm. b, d, e Immunofluorescence of CD45 positive cells (panleukocyte marker) in red. Nuclei are counterstained with DAPI (blue). Magnification ×200. Scale: 100 µm. a Pulmonary parenchyma of a sham mouse. The head of the arrow indicates an alveolar macrophage. b Infiltration of CD45 + cells in a sham mouse parenchyma. c WT CLP mouse parenchyma with acute histological pulmonary lesions characterized by alveolar septa thickening, polynuclear neutrophil infiltration and fibrin strands. d Infiltration of CD45 + cells in the parenchyma of a WT CLP mouse. e Pulmonary parenchyma of a WT CLP R-954 mouse. f Infiltration of CD45 + cells in the parenchyma of a WT CLP R-954 mouse. The white arrow indicates an alveolar macrophage. g Histological lesions of an acute lung injury: polynuclear neutrophils (blue arrows), intra-alveolar fibrin strands (stars), hyaline membrane (black arrow). h Mean Acute Lung Injury score for 5 fields per slide evaluated in a blind (optical microscopy, magnification ×400). WT sham: sham-operated C57BL/6J controls; WT CLP: CLP-induced septic C57BL/6J mice; WT CLP R-954: CLP-induced septic C57BL/6J mice that received prophylactic B1R antagonist R-954. Kruskal–Wallis test followed by a Dunn’s correction. n = 7 to 11 per group. *p < 0.05. Results expressed in median ± IQR