ESPE Abstracts

Background: Microplastics (MPs) are recognized as new type of environmental pollutants with potential implications for human health. It can exist in the human body for a long time, are not easy to degrade, and accumulate in various organs. Studies have shown that it has reproductive toxicity and can directly affect the female gonads, causing ovarian toxicity, granulosa cell apoptosis, affecting uterine function, and even leading to infertility. Precocious puberty (PP), as a common disorder of adolescent sexual development in girls, may be associated with the intake of MPs. This study aims to investigate the types and concentrations of MPs in the serum of girls with idiopathic central precocious puberty, and to analyze the molecular mechanism of MPs pollution interfering with female sexual development during puberty.

Methods: The types and concentrations of 11 MPs and 23 steroid hormones in the serum of girls with PP were analyzed by Py-GCMS. In order to explore the toxic effects of MPs on adolescent sexual development, young female rats were treated with different concentrations of MPs by gavage for two weeks.

Results: Py-GCMS analysis showed that the detection rates of PS, PE and PVC in the serum of PP girls were more than 95%. The levels of PE and PVC were significantly increased in the PP group, and were positively correlated with the progesterone and cortisol. According to the average concentrations of PE and PVC in PP, the young female rats were given gradient concentrations of PE or PVC by gavage. After 2 weeks of exposure, the vaginal open time female mice showed significantly advance, while there was no significant change in body weight among the groups. Microplastic infiltration was found in the brain, ovary, liver and stomach of female mice. The data indicated that MPs can be absorbed and enter the brain and gonad after gavage, and affect pubertal sexual development.

Conclusion: MPs, especially PE and PVC, are high risk factors affecting girls' adolescent sexual development. MPs can enter the hypothalamus and ovarian tissue through oral administration, affecting female adolescent sexual development.