Fig. 6.

Therapeutic effects of vitamin K₃ in the lipopolysaccharide (LPS)-induced acute respiratory distress syndrome (ARDS) mouse model. Male C57BL/6 mice were injected intraperitoneally with 15 mg/kg body weight (BW) LPS or saline as a vehicle control. After 30 min, the mice were injected intraperitoneally with 100 mg/kg BW vitamin K₃ or corn oil as vehicle control. (a) After 6 h the mice were killed, and the lung tissue was collected. The lung tissue was stained with haematoxylin & eosin (H&E ×400), and histopathological examination of the lung tissue was performed. Typical pictures are shown from at least triplicate determinations. (i) Negative control group; (ii) LPS group; (iii) LPS+vitamin K₃ group. The white arrow indicates oedematous change in the alveolar wall and the swelling of alveolar epithelial cells, and the black arrow indicates massive polymorphonuclear infiltration. (b,c). After 24 h the mice were killed, and total cell (b) and neutrophil (c) counts in the bronchoalveolar lavage (BAL) fluid were performed. Each data value is expressed as mean ± standard error, n = 3. The presence of significant differences is indicated by asterisks (P < 0·05).