Combined effect of cadmium, benzo(a)pyrene and pyrene on the Wistar male rats reproductive system

Heavy metal cadmium (Cd) and polycyclic aromatic hydrocarbons benzo(a)pyrene (B(a)P) and pyrene (P) are ubiquitous and persistent environmental pollutants. The human being is constantly exposed to mixtures of these substances. Cd and B(a)P have an adverse effect on reproductive function. According to some data, Cd and B(a)P or B(a)P and P may interact in some metabolism phases of xenobiotics. Objective of he study: To determine the combined action of Cd, B(a)P and P at different doses and duration on the reproductive system of Wistar male rats at the oral route of administration. Materials and methods: In the experiment, about 320 Wistar male rats were employed. The doses of Cd (0.1, 0.5, 1.92, 4.0 mg/kg), B(a)P (0.00015, 0.0015, 33.3, 10.0 mg/kg), P (0.00075, 0.0075, 20.0, 90.0 mg/kg) and their combinations and exposure duration in 14, 28, 90 days were tried. The combined effect of substances on the male rats reproductive system evaluated according to the parameters: amount of spermatozoids in the epididymic suspension, % of viable spermatozoids, their motility duration and resistance in 2 media (NaCl and HCl). By the end of experimental relative weight calculation of testicles, seminal vesicles and epididymis were performed, too. The effects of combinations were characterized by 4 types of combined action of substances: antagonistic, additive, synergic and unknown nature. Results: The effect of the Cd, B(a)P and P combinations on the Wistar male rats reproductive system most often was similar to the effect made by isolated substances. The toxic effect of experimental substances combinations was manifested by a reduction in amount of spermatozoids, in their viability, by shorter motility duration and the lower resistance in the media of NaCl and HCl. Conclusions: According to the tested parameters of the male rats reproductive system, 4 types of combined action of substances were identified: antagonistic (56%), additive (38%), synergic (4%) and of unknown nature (2%).