P-122: Effects of Cobalt Chloride and Chromium Chloride on Development of Mouse Testes

Background: Cobalt (Co) is an essential trace element for mammals required for the synthesis of vitamin B12. It is not a cumulative toxin but chronic exposure induces negative effects on the organism. It was proven that cobalt passes via placenta appearing in the fetal blood and amniotic fluid and it is shown to possess an embryotoxic effect. Also, chromium (Cr) is recognized as a trace element essential for both animal and human nutrition. Chromium has been shown to have antioxidative properties in vivo. In the present study, we focused on the effects of chronic exposure to cobalt chloride and chromium chloride on development of mouse testes. Materials and Methods: The mice were acclimatized for seven days prior to coupling and were housed in an air conditioned animal house at 22 ± 2°C with exposure to 10-12 hours of day light. Day zero of pregnancy was determined by vaginal plug test. Pregnant mice were administered cobalt chloride and chromium chloride intraperitoneally at the concentrations of Co-60, Co-50, Co-40, Co- 10, Cr-50, Co-10/Cr-50 and Co-40/Cr-50 mg/Kg bw on day 12-14 pregnancy. After pup’s delivery, male pups were sacrificed on day 35 and testes were removed, fixed in 10% neutral buffered formalin and embedded in paraffin wax. Serial sections (5μm) of the medullary area were obtained in each group and stained with hematoxylin-eosin. The sections were observed under light microscopy. For all experiments, at least 6 to 8 replicates were performed. The data were analyzed statistically using Chi square test and analysis of variance (ANOVA). A level of (p<0.05) was accepted as significant. Results: Our results showed that single dose ip injection of cobalt chloride caused miscarriage in dose dependent manner (60, 50 and 40 mg/kg). Also, cotreatment of cobalt chloride and chromium chloride improved rate of successful pregnancy in Co10/Cr50 and Co40/Cr50 mg/kg bw. Histological comparisons of control and treatment groups showed that cobalt chloride in 10 and 40 mg/kg bw decreased the number of spermatogonia, primary spermatocytes cells, sertoli cells and sperm. Chromium chloride in 50 mg/kg bw compensated toxic effects of cobalt chloride. Tubules number and tubules diameter decreased after exposure to cobalt chloride and cotreatment of cobalt chloride and chromium chlorid compensate this reduction. Conclusion: Cotreatment of cobalt chloride and chromium chlorid compensate the toxic effects of cobalt chloride on development of mouse testes in a dose dependent manner.