Fig. 1

Pathologic findings in the lung tissue, lung injury scores, and pulmonary edema. Representative histological images of each group are shown. Tissue sections were stained with hematoxylin and eosin (× 200). a Normal lung structures are shown in the control group. b Mild neutrophils infiltration was observed in the low TV group. c Significant thickening of alveolar septal walls, neutrophil infiltration, and alveolar edema can be observed in the VILI group. d Significantly reduced degrees of lung injury, including decreased edema and inflammatory cell infiltration, can be observed in the GnRb2 group. e The lung injury scores were significantly higher in the low TV, VILI, and GnRb2 group compared to the control group, respectively (low TV; p < 0.01, VILI; p < 0.001, GnRb2; p < 0.001). GnRb2 pretreatment significantly suppressed the increased lung injury scores induced by VILI (p < 0.001). f Mechanical ventilation markedly increased the wet-to-dry weight ratio. Wet-to-dry ratio was significantly higher in the low TV, VILI, and GnRb2 group, respectively (low TV; p < 0.01, VILI; p < 0.001, GnRb2; p < 0.001). Pretreatment with GnRb2 significantly reduced wet-to-dry weight ratios compared to the VILI group (p = 0.048) (n = 6 in each group). **p < 0.01 compared to control, ***p < 0.001 compared to control, ^#p < 0.05 compared to VILI, ^###p < 0.001 compared to VILI