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Effects of 52-Day Oral Exposure to Fluorescent Polystyrene Microplastics on Hormonal Profile, Sperm Parameters, and
Hristiyana Kanzova1, Madlena Andreeva1, Yana Goranova2
1Institute of Neurobiology, Bulgarian Academy of Sciences, Acad. Georgi Bonchev Str., Bl. 23, 1113 Sofia, Bulgaria.
Abstract:
Increasing environmental contamination with microplastics (MPs) raises significant concerns regarding their potential impact on reproductive health. This study evaluated the effects of prolonged oral exposure to fluorescent polystyrene microplastics (FPS-MPs) of different sizes on the male reproductive system in Wistar rats. Juvenile male rats at 21 days of age were exposed to FPS-MPs of 1 µm and 5 µm for 52 days, covering the period of sexual maturation and a complete spermatogenesis cycle. Body weight, reproductive organ indices, serum levels of testosterone (T), estradiol (E2), follicle-stimulating hormone (FSH), and luteinizing hormone (LH), as well as sperm motility and morphology, were assessed. Reproductive potential and accumulation of microplastics in reproductive tissues were also evaluated. No significant differences were observed in body weight or most reproductive organ indices, except for a slight reduction in the left epididymis index in the group exposed to 5 µm particles. FPS-MPs induced size-dependent changes in the hormonal profile, including decreases in T and E2 and compensatory increases in FSH and LH, as well as impairments in sperm quality, which were more pronounced in rats exposed to smaller particles. In conclusion, fertility potential remained preserved, while FPS-MPs accumulated in the testes and epididymides, demonstrating subclinical, size-dependent effects on the male reproductive system.
Insights
Microplastics (MPs) exposure in rats impacted male reproductive health, affecting hormones and sperm quality. Fertility remained preserved, but MPs accumulated in reproductive tissues, showing size-dependent effects.
Area of Science:
- Environmental Science
- Toxicology
- Reproductive Biology
Background:
- Microplastic (MP) contamination is a growing environmental concern.
- Potential impacts of MPs on human and animal reproductive health require thorough investigation.
Purpose of the Study:
- To assess the effects of prolonged oral exposure to fluorescent polystyrene microplastics (FPS-MPs) of varying sizes on the male reproductive system in Wistar rats.
- To evaluate hormonal profiles, sperm quality, reproductive organ indices, and MP accumulation in reproductive tissues.
Main Methods:
- Juvenile male Wistar rats were orally exposed to 1 µm and 5 µm FPS-MPs for 52 days.
- Evaluated body weight, reproductive organ indices, serum hormone levels (testosterone, estradiol, FSH, LH), sperm parameters, and MP accumulation.
- Assessed reproductive potential and tissue MP burden.
Main Results:
- No significant changes in body weight or most reproductive organ indices were observed.
- FPS-MPs induced size-dependent hormonal alterations, decreasing testosterone and estradiol while increasing FSH and LH.
- Sperm quality was impaired, with smaller MPs causing more pronounced effects; fertility potential was preserved.
- Microplastics were found to accumulate in testes and epididymides.
Conclusions:
- Prolonged exposure to FPS-MPs causes subclinical, size-dependent adverse effects on the male rat reproductive system.
- Hormonal balance and sperm quality are compromised, though fertility potential is maintained.
- Microplastic accumulation in reproductive tissues highlights potential long-term risks.
