Perinatal exposure to polystyrene microplastics: biometric, hormonal and behavioral parameters of male and female Wistar rats at weaning, puberty and adulthood.

Microplastics (MPs) are widespread in environment, being detected in human tissues, as placenta and breast milk. Given their potential endocrine and neurobehavioral effects, we studied whether perinatal exposure to MPs causes dysfunctions in dams and offspring. From gestational day 7 (G7) until weaning, Wistar rat dams received water (control group; n = 9) or 10 μm polystyrene microparticles (25 μg/kg body mass, MP group; n = 8). Biometric and biochemical parameters of dams and offspring were evaluated at weaning (21 days-old), puberty (45 days-old) and adulthood (120 days-old). Behavioral tests were performed at puberty and adulthood. MP dams showed lower body mass from the G10 until delivery but returned to control levels during lactation; also exhibited lower plasma cholesterol and T4 levels at weaning. MP offspring showed age- and sex-dependent alterations in lipid and endocrine homeostasis, including changes in cholesterol, triglycerides, corticosterone, thyroid hormones, leptin and FSH levels. Adult offspring also showed sex-specific behavioral alterations. MP males showed increased anxiety-like behavior during puberty and adulthood, reduced caloric intake and preference for the high-fat diet whereas adult females exhibited increased caloric intake. Thus, perinatal exposure to a single dose of 10-μm polystyrene microplastics was associated with behavior, lipid and endocrine disturbances in both dams and offspring.