Fig 1. Replacement of vacuolated foetal-type epithelium by non-vacuolated adult-type epithelium in the distal part of the SI during postnatal development in rats.

(a) Representative H & E stained sections (magnification 400x) showing the structural changes in the distal SI between the suckling (7d) and the post-weaning periods (28d). (b) Appearance of adult-type epithelium with non-vacuolated cells (in % of total villous length) in 7, 14, 21, 28 and 35 days old rats (mean ± SD, n = 6–7).