Background: Maternal protein restriction causes sperm alterations in the offspring,
most of which are associated with epididymal functions. Because fluid reabsorption/secretion
dynamics in the epididymal environment play important roles in the process of sperm
maturation and concentration, we investigated the effects of maternal protein restriction
on the expression of aquaporins (AQP1 and AQP9), vascular endothelial growth factor
(VEGFa), and its receptor VEGFr-2 in different stages of postnatal epididymal development.
Methods: Pregnant rats were divided into groups that received normoprotein (17% protein)
and low-protein diets (6% protein) during gestation and lactation. After weaning,
male rats only received the standard diet and were euthanized at the predetermined
ages of 21, 44 and 120 days. Results: Maternal protein restriction decreased AQP1
and AQP9 expression in the initial segment and caput epididymis compared to the increased
expression of these proteins observed in the corpus and cauda at all ages. Although
protein restriction reduced the microvasculature density (MVD) on postnatal day (PND)
21 and 44, the MVD was unaltered on PND 120. Conclusions: Maternal protein restriction
changed the structure or function of the offspring's epididymis, specifically by affecting
fluid dynamics and vasculogenesis in important stages of epididymis development.