Figure 1: PDE5 expression at different stages of rat lung development. Upper panel: representative western blot analysis of adult lung (ALu), 14 day-old lung (P14Lu), 3 day-old lung (P3Lu), adult lung incubated in presence of PDE5-peptide (ALu+peptide). N18 cell culture (N18) was utilised as standard of PDE5. Each lane was loaded with 50 g of protein. Lower panel: densitometric quantification of immunoreactive PDE5 and actin bands. Data are mean ± SD of 3 different experiments. Differences were not significant (ANOVA test).