Fig. 2. Effect of ventilation and hydrogen sulfide (H2S) treatment on lung injury. As controls, mice were subjected to spontaneously breathe either air (A ) or 80 ppm H2S (C ) or were ventilated (vent) with 12 ml/kg for 6 h with either synthetic air (B ) or synthetic air + 80 ppm H2S (D ). The sections from the left lung lobe were hematoxylin and eosin stained. Representative pictures are shown for each experimental group (magnification ×400, A -D ). High-power fields were randomly assigned per photograph to measure alveolar wall thickness (E ) and ventilator-induced lung injury (VILI) score (F ). Data represent means ± SEM for n = 6/group. Analysis of variance (Student-Newman-Keuls post hoc test), *P < 0.05 versus control; # P < 0.05 versus H2S control; §P < 0.05 versus H2S-ventilated group.