Toxic Effect of Cadmium Chloride Exposure on Teeth Development in Sprague Dawley Rats During Pregnancy

Abstract

Background: Cadmium chloride (CdCl2) is a widely spread environmental toxin with reported developmental toxicity. Aim:The aim of the present work was to investigate the developmental toxicity of CdCl2 on rats' first molar histological structure, teeth mineralization through osteocalcin staining and evaluating caspase-3 expression as potential target, both intrauterine and after birth. Methods: Adult male and female Sprague Dawley rats were mated. Pregnant rats were divided into 2 groups, control group received water and experimental group received CdCl2 (5mg/kg) by oral gavage from 7 th to 17 th day of pregnancy. Two rats from control group and 8 rats from experimental group were sacrificed at gestational day 17 (GD17). Fifteen pups were obtained in control group and 10 pups in CdCl2 group. The day of parturition was deigned to be postnatal day (PND) zero (PND 0). From control group, 13 pups were sacrificed at PND10, and 13 pups at PND 20. From experimental groups, 12 pups were sacrificed at PND10, and 11 pups at PND 20. In all pups, heads were obtained for examining maxillary first molars. Results: Sections from the CdCl2 group showed delayed development, mineralization, and eruption of first molar than the control group in GD17, PND10 and PND 20. As regard osteocalcin, the expression pattern was the same in both groups, but the intensity of the expression decreased within the CdCl2 group with statistically significant difference between them. In addition, caspase-3 expression increased indicating apoptosis induction. Conclusion: Exposure to CdCl2 during pregnancy can lead to delay in the developmental stages of the first molar teeth beside its effect on the mineralization of dentin, the delayed teeth eruption and inducing apoptosis is a possible pathway for these effects.