Orally Subchronic Exposure to Benzo[a]pyrene Alters Reproductive Hormone Profile

The objective of this article was to assess whether benzo(a)pyrene (B[a]P) alters reproductive hormones, which in turn leads to decreased spermatozoa quality and spermatogenic cell levels. Hsd: ICR (CD1) 10-week old males were orally exposed to B[a]P at 1, 10, 50, and 100 mg/kg/day of body weight for 30 and 60 days. At the end of the experiment, mice were anesthetized and reproductive tissues, i.e., testes, seminal vesicles, and epididymis, were collected. Spermatogenic cells and mature spermatozoa were recovered from the testes and cauda epididymis, respectively. Spermatozoa quality, including concentration, morphology, motility, and viability, was examined. Testosterone, estradiol, follicle stimulating hormone (FSH), and luteinizing hormone (LH) levels in serum were determined using the Enzyme Immunoassay/Enzyme Linked Immunosorbent Assay (EIA/ELISA). Mice exposed to B[a]P at 50 mg/kg/day and 100 mg/kg/day for 30 days and 60 days exhibited a significantly decrease in serum testosterone and estradiol levels as compared with the control, while FSH and LH remained stable. The levels of testosterone and estradiol were positively correlated with decreased spermatozoa motility (p = 0.025 and 0.014, respectively), viability (p = 0.002 and 0.018, respectively), and morphology (p = 0.007 and 0.018, respectively), but the hormone levels did not correlate with spermatozoa levels. The testosterone and estradiol levels did not correlate with the levels of spermatogonia, pachytene spermatocytes, round spermatids, and elongated spermatids. Subchronic exposure to B[a]P could modulate the production of testosterone and estradiol, which subsequently influence spermatozoa quality.