Histological Assessment of Placental Development Following Intrauterine Exposure to Carbon Tetrachloride (CCl₄) in Pregnant Wistar Rats

Abstract

Background/Objectives: In recent years, attention has been drawn to concerns regarding human reproductive disorders, particularly in relation to optimal fetal development during pregnancy. Several studies on carbon tetrachloride (CCL₄) toxicity have focused on maternal health with very little attention on placental and fetal health. Placenta is a vital organ that facilitates the exchange of nutrient between mother and fetus. This study assessed placental development following intrauterine exposure to CCL₄ in pregnant Wistar rats. Materials and Methods: Thirty (30) adult Wistar rats weighing between 170 g -180 g were utilized, paired overnight at an estrous cycle with sexually active males at 2:1 ratio. Pregnancy was confirmed by the presence of vaginal plug and/or sperm in the vaginal smear vaginal lavage and the day was recorded as gestational day (GD) 0. The pregnant rats were divided into two (2) groups (A and B) with fifteen (15) rats per group. Group A served as Control and was administered with a single intra-peritoneal injection of 2 ml of olive oil on GD 11, while Group B served as the treated group and was administered with a single intra-peritoneal injection of 2 ml of CCl₄/olive oil (1:1, volume for volume) on GD11. On GD15, GD17 and GD19, five rats were sampled from each group and their placentas were harvested for histological assessment.

Result and conclusion: Histological studies showed normal placental development in the control group and varying alterations in placental histomorphology, ranging from vacuolar degeneration of the glycogen cells in the junctional zone and discoloration indicating necrotic changes as well as dilated sinusoids in the labyrinth zone. In conclusion, histomorphological evidence suggests that CCl₄ administration adversely affects placental development in Wistar rats.