Figure 3.

Immunohistochemistry for vascular endothelial growth factor (VEGF) in the lungs of control (a, c, e, g) and vitamin A treated (b, d, f, h) foetuses and neonates. Higher intensity and distribution of VEGF immunoexpression patterns in control foetuses at the 15th gestational (a, b). Strong VEGF immunoexpression, both for control and for treated foetuses at the 17th gestational day (c, d). The central area depicted in (c) displays fewer immunoexpressing cells. Higher immunoexpression in treated foetuses at the 18th gestational day (f). The intensity and distribution expression patterns are different in contiguous areas of the saccular parenchyma. Similar immunoexpression for VEGF in control and treated neonates (g, h). Notice the weak or absent immunoexpression in the cuboidal epithelium of the distal airways. Original magnification ×400 (a, b and e, f). Original magnification ×200 (c, d and g, h).