JBRA Assisted Reproduction 2025;29(Suppl.2 SBRA 2025):165
Poster Presentation
29^th Annual Congress of the SBRA. São Paulo/SP - Brazil, 2025
doi: 10.5935/1518-0557.20263924

P-153. Low-Dose N-Nitrosodimethylamine Exposure Impairs Sperm Parameters in Wistar Rats: Implications for Male Reproductive Health

Otávio Galassi Vitale¹, Lívia Trippe Nagaoka¹, Julia Stein¹, Giovanna Kugel Marraschi¹, Giovanna Ferrari Rosalem¹, Luara Magalhães¹, Reggina Lorena Mellado Castro¹, Sara Tawany Caetano Dos Santos¹, Júlia Vitória Francisco de Aquino¹, Júlia Taveres Alves¹, Bárbara Campos Jorge¹, Arielle Cristina Arena¹

¹ Instituto de Biociências de Botucatu - IBB UNESP – Botucatu – SP - Brasil

Objective: Male infertility is a growing global health issue, often linked to reduced sperm counts and hormonal imbalances. Environmental contaminants, such as N-nitrosodimethylamine (NDMA)—a widespread nitrosamine found in food, medications, cigarettes, and drinking water —have raised concerns due to their mutagenic, carcinogenic, and potential endocrine-disrupting properties. Despite regulatory limits set by agencies like the FDA, which established an Acceptable Daily Intake (ADI) of 96 ng/day for NDMA in humans, its reproductive effects, especially at low doses, remain poorly investigated. This study aimed to evaluate the effects of low-dose N-nitrosodimethylamine (NDMA)—the most commonly detected nitrosamine in the environment—on sperm parameters in adult male Wistar rats.
Methods: A total of 44 male rats were used in the experimental model (CEUA: 4704260423) and divided into two groups: the Control Group, which received 1 ml/kg/day of distilled water, and the NDMA Group, exposed to 7.2 ng/kg/day of NDMA. Exposure was administered orally via gavage from postnatal day (PND) 60 to 105. At the end of the exposure period, animals were euthanized for collection of reproductive organs, which were analyzed for morphology, sperm count, motility, and sperm kinetics, among other parameters. Statistical differences were considered significant at p<0.05.
Results: Both absolute (p=0.02) and relative (p=0.01) prostate weights were increased in the NDMA-exposed animals compared to the control group. No significant differences were observed in sperm morphology between groups; however, sperm count was altered across all testicular parameters, with a reduction in the absolute (p=0.011) and relative (p=0.038) number of mature spermatids and daily sperm production. In both regions of the epididymis analyzed (caput/corpus and cauda), an increase in sperm transit time was observed in NDMA-exposed animals (p=0.001). Sperm motility is a highly relevant parameter for male fertility. In this study, motility parameters (%) showed a reduction in total motile sperm (p=0.04), an increase in progressive motility (p=0.04), and a higher proportion of slow-moving (p=0.02) and static sperm (p=0.04). Sperm kinetics were also affected, with a decrease in Amplitude of Lateral Head Displacement (ALH) (p=0.008) and Wobble coefficient (WOB) (p=0.011), indicating that NDMA may impair sperm movement characteristics. The observed reproductive toxicity may be associated with hormonal imbalance and/or direct damage to germ cells, both potentially caused by NDMA exposure.
Conclusion: Even at the established ADI, NDMA triggered significant reproductive effects in male rats, particularly in sperm parameters. Future analyses will help clarify the mechanisms underlying NDMA-induced toxicity in these parameters, and further studies are needed to better assess the impact of this contaminant on human reproductive health and guide future regulatory decisions.