Study On Effect And Mechanism Of Lead Acetate On Reproduction And Embryonic Development Of Female Mice

With the rapid development of global economic and industrialization,lead is a kind of heavy metal which is widely used in industry,environmental pollution has become a hot topic of great concern to the whole society.Lead in the body has long half-life,accumulating for a long time in the body of animals and humans and causing serious harm to the reproductive systems of animals and humans.How to eliminate or reduce the harm of lead to animals and humans has become an urgent problem to be solved in the production.In this experiment,effects of lead acetate on the growth and development of ovaries and uterus were studied by making female mice drink different doses of lead acetate solution(P <0.05).The expression level of Bcl-2,Bax and P53 were detected by RT-PCR.The effects of lead acetate on the reproductive system of female mice were revealed on the molecular level.The study can provide reference and basic knowledge information about lead reproductive toxicology research and chronic lead poisoning prevention and control of clinical pre-mature animal,including cattle,sheep and other economic animals,else livestock and even human.The results were as following:1.Effects of different doses of lead acetate on embryonic development of female miceStudy the effects of lead acetate on reproductive and embryonic development of female rats by making female mice drink different doses of lead acetate solution to establish a mouse poisoning model.The results indicated the average number of oviposition in 900mg/L dose group is significantly lower than that in 600mg/L,300mg/L and the control group(P <0.05),but 300mg/L and 600mg/L dose group as close same as the control group(P> 0.05).The average number of embryos in the 900 mg /Ldose group is significantly lower than that in the 600 mg / L dose group(P <0.05),and is significantly lower than those in 300 mg /L dose group and the control group(P<0.01).These two indicators of 600mg/L dose group also significantly lower than those in 300 mg / L dose group.There is no significant difference,the average number of embryos and blastocysts and the number of blastocysts,between the 300mg/L dose group and the control group(P> 0.05).The average number of degenerated embryos and delayed embryo of 900 mg / L dose group are significantly higher than those of600 mg / L,300 mg / L and the control group(P <0.05),but no significant difference between other dose group and the control group.There is no difference,average number of unfertilized eggs,between the 900 mg/L dose group and the 600 mg/L dose group(P> 0.05),but it is significantly higher than that of the 300mg/L dose group and the control group(P <0.05).There is no significant difference between the 300 mg /L dose group and the control group(P> 0.05).The results show that the total number of embryos is decreasing and the number of morula and blastocysts is decreasing with the increasing dose of lead acetate,while the number of delayed embryo,degenerated embryos and unfertilized eggs is increasing,which indicates that lead suppresses the normal development of embryos.2.Effects of different doses of lead acetate on the content of hormones and the conception and yield of female miceAs the mice drinks lead acetate solution in a long-term,female mice ovarian function damaged,causing the amount of progesterone secretion of corpus luteum decreased significantly.The results indicate that: there was no significant difference of area under curve of progesterone between 900 mg/L dose group and 600 mg /L dose group(P >0.05),but that in 900 mg / L dose group lower than 300 mg/L dose group and the control group(P <0.05),and the difference between 300 mg/L dose group and the control group was not significant(P>0.05).This may be the most important reason of delayed and degenerative development of embryos,so ultimately affect the conception rate and numbers of births of female mice.3.Effects of different doses of lead acetate on P53,Bax,Bcl-2 gene expressionLead in the body can act directly on the ovarian tissue.Firstly lead-induced gene regulation affect the apoptosis of follicular granulocytes which result reduced estrogen secretion to the impact on the reproductive system.Through quantitative PCR detection of Bcl-2,Bax and P53,the results show that lead could up regulate the expression of P53 and Bax in ovarian granulosa cells and down regulate the expression of apoptotic gene Bcl-2 inducing apoptosis of ovarian granulosa cells.