The Effect of Cadmium on Hippocampus Development of Rat Embryos and L-carnitine Protective Role

Background and Objectives: Cadmium is a toxic metal which is widely used in industry. This metal exerts toxic effects on multiple organs, including nervous system. The aim of this study is to evaluate the effect of cadmium on weight and development of hippocampus in Wistar rat embryos and then determining whether L-carnitine, as an antioxidant, can protect hippocampus from the toxic effects.Methods: Female Wistar rats (250-300g) were used in this study. 24 hours after mating with male rats, the females were separated and their vaginal smears were examined for sperm detection. This day was considered as embryonic zero day. The female rats were divided into three groups: The control group which received no injection, the experimental group 1 which received 1mg/kg B.W cadmium and the experimental group 2 which received 1mg/kg B.W cadmium+500mg/kg B.W L-carnitin in days 7 and 10 of gestation. On day 17 of gestation, the animals were sacrificed by chloroform over dose and their embryos were removed surgically. The embryos were fixed in formalin 10% for 30 days, the weight of embryos were measured. Then tissue processing, sectioning and Hematoxylin-Eosin (H & M) staining were done. Some sections of hippocampus were evaluated using light microscope and MOTIC soft ware. Results: The weight of embryos were significantly decreased in experimental groups. This decrease was significantly greater in the Experimental group 2. The number of cells and thickness of hippocampus layers were decreased significantly just in the second group. Conclusion: These findings indicate that cadmium has teratogenic effects on embryo’s weight and development of hippocampus and at least a part of these effects may be inhibited by L-carnitine.