Maternal nutritional restriction modulates placental VEGF immunolocalization and fetoplacental development in the rabbit

Abstract

Maternal nutritional disorders during pregnancy can modify placental vascularization and therefore, fetal development. The aim of this work was to assess the effect of a feed restriction of 60% of the nutritional requirements during pregnancy on fetoplacental development, placental efficiency (fetal/placental weight) and expression of vascular endothelial growth factor (VEGF) in the rabbit. Multiparous pregnant rabbits were fed ad libitum (C; n = 17) or food restricted (R021, n = 25) from day (D) 0 to D21. On D28, 11 dams were euthanized to study fetoplacental features and the rest (n = 31) were used to assess perinatal survival and birth weight. Immunohistochemical studies of paraffined placentae (ABC method) was performed for VEGF. No differences were found in the number of viable fetuses between C and R021 groups (11.6 ± 2.9 vs. 12.0 ± 2.0). However, fetuses of C group showed higher size (thoracic diameter: 20.5 ± 2.8 vs. 19.1 ± 1.8 mm, occipital-nasal length: 29.0 ± 1.4 vs. 27.9 ± 1.4 mm); total weight (39.2 ± 7.3 vs. 34.7 ± 5–9 g), and separated head and body weights (9.1 ± 1.5 vs. 8.1 ± 1.1 and 29.3 ± 6.0 vs. 25.6 ± 4.8 g, respectively) than R021 (p < 0.05). Placental efficiency was lower in R021 than in C group (p < 0.05). VEGF was mainly immunolocalized in endothelial cells in labyrinth zone in both groups being slightly intensive in C group. Mean number of born alive per doe (10.4 ± 3.0 vs. 12.3 ± 3.1) and their weight (59.1 ± 9.8 vs. 56.4 ± 6.8 g) were similar between groups. In conclusion, maternal feed restriction seems to modulate VEGF expression, placental efficiency and fetal development in the rabbit. These effects were not reflected in a low body weight at parturition. (Funds by AGL2015-65572-C2.