Histological and Morphological Study of the Intestines of Wistar Rat Fetuses in a Modified Gastroschisis Experimental Model

Abstract

In gastroschisis (G), the lesion degree of exposed intestinal segments is related to the time of its contact with the amniotic fluid (AF) and exposure to meconium which is the cause of intestinal morphological and histological alterations. The outcome of these alterations is intestinal hypoperistalsis and nutrient absorption deficiency, which contribute to increased morbidity and high medical-hospital costs. In this study, morphological and histological intestine alterations were identified at two different contact occasions with AF. Experimental gastroschisis (G) was performed on Wistar rat fetuses at a single gestational age on day 18.5 th . The fetuses were removed on the 20.5 th (G-1) and 21.5 th days (G-2). Fetuses of both groups were divided in 3 sub-groups: control (C), gastroschisis (G) and sham (S). Measurements were taken of the Whole Set including fetus, placenta and membranes with AF (WS), fetus body weight (BW), intestinal weight (IW) and their diameters (DI). The objective of the present study is to test a new gastroschisis experimental model and identify differences in morphological and histological alterations in these two gestational periods that may be directly related to intestinal motility disorders in G. The WS and BW presented no significant statistical difference when compared G1 and G2. The results of the intestine average weight of G2 fetuses were significantly higher when compared to G1 fetuses in all subgroups (C: p = 0.02; G: p = 0.01; S: p = 0.02, Mann Whitney ). The results of the intestinal average diameters (D/d) in G1 and G2 presented significant statistical difference only in G subgroup (p Kruskal Wallis ). When compared intestinal average diameters, there was significant statistical difference of G fetuses in G1 and G2 (p Mann Whitney ). In conclusion, the present experimental G model was adequate to reproduce G in rat fetuses. All G fetuses presented significant statistical difference when compared to other group in their subgroup and when compared G1 and G2 (p < 0.05). These alterations can explain the difficulties in accomplishing adequate peristalsis in G neonate bearers.