Male reproductive impacts of styrene in rat.

To determine the effect of styrene on the male reproductive function of rats, male Wistar rats received a daily intraperitoneal (ip) injection of the xenobiotic at a dose of 600 mg/kg body weight. Serum testosterone (T) level was measured in duplicate by radioimmunoassay (RIA). Blood luteinizing hormone (LH) and follicle stimulating hormone (FSH) concentrations were determined using enzyme-linked immunosorbent assay (ELISA). After 10 days of treatment, an increase of the relative weight of the testis occurred, but that of the seminal vesicles and prostate remained unchanged compared to controls injected with an equivalent volume of the vehicle (corn oil). Serum T concentration dropped, while serum hypophyse hormone levels increased. Testicular histological observations revealed a pronounced morphological alteration, with enlarged intracellular spaces, loosening of tissue, and dramatic loss of gametes in the lumen of the seminiferous tubules. Spermatogenesis damage was also confirmed by the decrease in motility and the number of epididymal spermatozoa of treated rats. According to these results, with regard to the lack of a dose response relationship in this study, we may conclude that the testis, precisely the germinal and Sertoli cells, are the major targets for styrene toxicity.