Fig. 2

Cell death in the CP and EL during normoxia and after hypoxemia. Pannels A and C images A–D are typical images obtained for CP (2A) and EL (2C) after normoxia, 24 h hypoxemia, 48 h hypoxemia and 48 h hypoxemia followed by 24 h recovery, respectively. The nuclei are stained with DAPI (blue) and dead cells are identified as TUNEL-positive (green). The bar is 50 μm. Arrows in 2C indicate EL. B and D. The graphs represent the graphs represent raw data in each group and the mean ± SD in CPs (2B) and ELs (2D) during normoxia (N, n = 6); 24 h hypoxemia (H24, n = 5), 48 h hypoxemia (H48, n = 5) and 24 h hypoxemia followed by the recovery (H48 + N24, n = 5). Shapiro- Wilk’s test for normality and Levene’s test for homogeneity of variance were not significant (p > 0.05). The duration of hypoxemia showed a significant increase in cell death in both CPs and EL (P < 0.01). Bonferroni test was used for multiple comparisons between the groups. Signs indicate: *—p < 0.05 N vs. other groups, #—p < 0.05 H48 + N24 vs. H24 and H48. E and F. TEM morphology of the CP epithelium after normoxia (1E) and hypoxemia (1F). The bar is 1 μm. Solid black arrows—microvilli; solid white arrows—mitochondria; dashed white arrow—nucleolus; dashed red arrow—chromatin; dashed yellow arrows—vacuoles