Effect Of Iodoacetic Acid On Mouse Oocytes

Disinfection of drinking water is an important public health achievement in the 20th century.Disinfection of drinking water with disinfectant can effectively remove the original microorganisms in the source water,thus reducing the occurrence of infectious diseases.However,in the process of disinfection with drinking water,disinfectants inevitably react with organic substances in water to form disinfection by-products.Iodine is a naturally occurring element in natural water,and its concentration is usually between 0.5 and 100 g/L.Iodine disinfection by-products（Iodine disinfection by-product,I-DBPs）are often formed during the oxidation treatment of drinking water.The formation of I-DBPs is mainly related to the smell and taste of tap water in production.Iodoacetic acid（iodoacetic acid,IAA）is a by-product of water disinfection,a colorless or white crystal,which is more toxic than bromide and chloride as an in vitro ovarian poison.It has powerful destructive and toxicological effects on the environment.Humans or animals are exposed to disinfection by-products through various channels,which will pose a threat to human or animal health.Toxicological studies have proved that they have cytotoxicity,carcinogenicity,hepatotoxicity,retinotoxicity,genetic toxicity and reproductive toxicity,etc.Female reproduction refers to the process in which organisms produce offspring and reproduce races,including endocrine regulation of oogenesis,generation and development of follicles,meiosis and maturation of eggs,formation and implantation of fertilized eggs,formation and development of embryos,etc.The normal reproductive development process also depends on the environment to a great extent.If environmental pollution appears in every link of the reproductive process,it may lead to reproductive damage,reduced fertility,fetal growth retardation,abortion and neonatal defects.Oocyte is an oocyte produced by meiosis during egg maturation.Among them,primary oocytes are produced after the differentiation of oocytes and DNA replication and division;Secondary oocytes are produced after the first meiosis;Mature oocytes are the products after the second meiosis.At present,iodoacetic acid has cytotoxicity,hepatotoxicity and retinal toxicity to animals,and it has been proved to be toxic to oocyte maturation in mice in vitro,leading to metaphase stagnation and polar body extrusion failure of mouse oocytes,reducing follicular growth,increasing the expression of pro-apoptosis factors,reducing the expression of anti-apoptosis factors,abnormal spindle assembly and chromosome dislocation.However,the effect of iodoacetic acid in vivo on the damage of mouse oocytes has not been studied,so observing the changes of mouse oocytes by iodoacetic acid in vivo will help researchers to provide a new basis for the study of reproductive toxicity of iodoacetic acid to animals.In our study,the toxicity model of mice was established by intragastric administration of iodoacetic acid.By Western blot and Immunofluorescence staining,it was found that iodoacetic acid could reduce the body weight and ovarian coefficient of mice,and the apoptosis rate of ovarian granulosa cells in iodoacetic acid treatment group was higher.The results showed that IAA exposure could reduce the weight of mice.IAA decreased the ovarian coefficient of mice.The ovarian coefficient of mice in control group was 3.0829x10^-4±0.1221x10^-4,and that of mice in high dose was 2.2614x10^-4±0.2031x10^-4.IAA decreased the number of oocytes in GV stage,which was 45.00±5.29 in the control group and 18±10.89 in the high-dose IAA group.IAA can also cause depolarization of mitochondrial membrane potential,increase cell apoptosis,increase cell iron death,abnormal distribution of lysosomes,increase cell oxidative stress,and then lead to oocyte damage.