Late impacts of intrauterine and lactational exposure to environmental plastic waste on testicular development with emphasis on the blood-testicular barrier

Abstract

The increase in the rate of production and use of plastics has generated concerns and discussions about environmental pollution and consequent contamination of organisms. In the environment, plastics are degraded into micro and nanoplastics (MNPs) that, due to the size of their particles, penetrate the human body. As a complication, chemical agents, phthalates, are added to the production of flexible plastics. These are easily released during polymer degradation and can disrupt cellular pathways of endocrine control and interfere with hormonal homeostasis. In this context, based on the DOHaD theory, exposure to these compounds during development can have consequences for the adult life of the offspring. Thus, this study aims to investigate the impacts of maternal exposure to a mixture of phthalates and nanoplastics during the prenatal and lactation periods, focusing on the testicular development of rat offspring. The objective is to identify possible structural and functional changes in adult rats, especially those associated with Sertoli cells, which are responsible for maintaining spermatogenesis through the formation of the blood-testis barrier (BTB). For this purpose, pregnant SD rats will be distributed into 4 groups: C: (control); T1: 20 µg/kg/day of the phthalate mixture (MF); T2: 100 nm polystyrene nanospheres (NPs) at a concentration of 1.0 mg/kg/day diluted in distilled water; T3: 20 µg/kg/day of MF + 100 nm NPs at a concentration of 1.0 mg/kg. The male offspring will have their testes collected in adulthood (PND 120) and will be intended for histological and morphometric, immunohistochemical and molecular (RT-qPCR) analyses. Molecular analyses will evaluate the gene expression of targets related to the maintenance of the BTB.