Figure 4.

Western Blot analysis of DDAH1 (A) and DDAH2 (B) protein in lung homogenates from wild-type and DDAH1⁻/⁻ mice kept under normoxia or hypoxia for 4 weeks. Protein expression was normalized to ß-tubulin, and to wild-type mice under normoxia as control group. Data are mean ± SEM of 4–5 animals per group. ^*p < 0.05; ^**p < 0.0001 as indicated; n.s., not significant; n.d., not detectable. NX, normoxia (21% O₂); HX, hypoxia (10% O₂).