INFLUENCE OF CADMIUM SALTS (CHLORIDE AND CITRATE) ON RAT EMBRYOGENESIS INDICATORS

Abstract

Accumulation of cadmium is a serious problem for residents of megacities. It has been established that cadmium has carcinogenic, gonadotropic, embryotropic, mutagenic, nephrotoxic and genotoxic effects, but scientific data on the effect on the general course of embryogenesis are extremely insufficient, and the reported research results are contradictory and cannot be compared due to the large difference in doses, methods of administration, etc. The aim of our study was to determine experimentally the effect of low doses of cadmium compounds (chloride and citrate) on the overall course of rat embryogenesis with isolated intragastric administration. Determination of the potential embryotoxic effect of cadmium compounds (chloride and citrate) was performed by calculating and comparing standard indicators of embryonic development, which are: average fetal number, total embryonic mortality, pre-implantation embryonic mortality and post-implantation embryo. Determinations were performed on the 13th and 20th days of embryogenesis. Young female Wistar rats weighing 170-200 g were used for the study. The experimental animals were divided into 3 groups (control, group of cadmium chloride (E №1) and cadmium citrate (E №2). From the first to the nineteenth day of pregnancy, females received according to the group saline solution, or solutions of cadmium citrate at a dose of 1.0 mg/kg, cadmium chloride at a dose of 1.0 mg/kg body weight enterally through a tube once a dayOn the 13th and 19th day of pregnancy, females were killed under thiopental anesthesia. The embryos were weighed and fixed in 10% formalin solution for further morphometric studies. The number of resorptions, live and dead fetuses in each corner of the uterus and corpora lutea in the ovaries of the respective side were counted. In the group of exposure to cadmium chloride (D№1) significantly increased rates of total embryonic mortality (TEM) in 3.7 times (p <0.001) and 3.2 times (p <0.001) on the 13th and 20th days of embryogenesis, indicators of preimplantation (PMU) in 6.5 times on the 13th day pregnancy (p <0.001) and 14.0 times on the 20th day of pregnancy (p <0.001), postimplantation embryonic mortality (PEU) indicators increased insignificantly by 3.0 times on the 13th day of pregnancy and 2.5 times on the 20th day of pregnancy with a decrease in the number of living fetuses per 1 female on the 13th day – by 24.04% (p <0.001), and on the 20th day – by 25.92% (p <0.01) compared with the control group. In the experimental group №2 action of cadmium citrate, the indicators of TEM increased 4.0 times (p <0.001) on the 13th and 3.2 times (p <0.001) on the 20th day of embryogenesis, the indicators of PMU in 6.0 times on the 13th day of pregnancy (p <0.01) and 11.0 times on the 20th day of pregnancy (p <0.01), PEU indicators increased insignificantly 3.0 times on the 13th day of pregnancy and 2.3 times on the 20th day of pregnancy with a decrease in the number of live fetuses per 1 female on the 13th day – by 18.27% (p <0.001), and on the 20th day – by 19.44% (p <0.05) relative to the control group. The analysis of the obtained results testifies to the pronounced embryotoxic effect of cadmium compounds on the processes of embryogenesis, which was manifested by a significant increase in overall embryonic mortality, preimplantation and postimplantation mortality in comparison with the control group on both studied embryonic embryogenesis.

Keywords

• embryogenesis
• embryonic mortality
• cadmium chloride
• cadmium citrate
• experiment.