Environmental chemicals are thought to adversely affect human reproductive function, however there are no studies that have explored the association between failed fertilization and exposure of both partners to environmental contaminants. Therefore, we collected blood and follicular fluid from the female partner and seminal plasma from the male partner of 21 couples attending an in vitro fertilization (IVF) program, in order to determine the extent of the existence of environmental chemicals in these fluids. Any relationship to the outcome of IVF was also considered. Sera and fluids were analysed for a variety of contaminants, including polychlorinated biphenyls, pesticides, cotinine, and the steroids progesterone and estradiol. Of the couples examined, 18 had fertilizations, three of whom became pregnant. There were no fertilizations in three other couples. The contaminants most frequently found in follicular fluid, more than 50% of the samples tested, were p,p'-DDE, mirex, hexachloroethane, 1,2,4-trichlorobenzene, PCB 49, PCB 153, and PCB 180. Cadmium was detected in eight of 21 (38.1%) samples of follicular fluid whereas cotinine was detected in 18 (85.7%). Residue levels of p,p'-DDE, endosulfan I, PCB 99, PCB 138, PCB 153, PCB 180 were quantified in more than 50% of the sera samples examined. Seminal plasma was relatively free of pollutants with mirex being the most frequently detected contaminant found in seven of 21 (33.3%) samples. Mirex could not be detected in the seminal plasma of the husbands whose partner's oocytes failed to fertilize whereas significant levels of mirex were found in the seminal plasma of all couples who had a pregnancy. Cadmium was also found in the follicular fluid of these pregnant subjects. No relationship was found between follicular fluid cotinine in pregnant and non-pregnant subjects. Where identical contaminants were found in both sera and follicular fluids, the levels were about twofold higher in serum and were positively correlated in both fluids. Fertilization was negatively correlated with serum and follicular fluid p,p'-DDE whereas pregnancy was positively correlated with follicular fluid PCB 49. These data reveal that more than 50% of the population of women attending a fertility program have had exposure to environmental chemicals sufficient to produce detectable concentrations in their serum and ovarian follicular fluid. Of the chemical contaminants detected in the serum and follicular fluid of these women, p,p'-DDE was the most frequently detected, had the highest residue levels, and was associated with failed fertilization.

No abstract

Benzo[a]pyrene (BaP) is an agonistic ligand for the aryl hydrocarbon receptor (AhR) and a major environmental carcinogen implicated in the aetiology of lung cancer through the induction of benzo[a]pyrene diol epoxidation (BPDE) and BPDE-DNA adducts. Because BaP metabolization requires cytochrome P-450 1A1 (CYP1A1) induction through activation of the AhR, we hypothesized that resveratrol, a natural competitive inhibitor of AhR, could prevent these adverse effects of BaP on the lung. Balb-C mice were injected for 5 weeks with corn oil, BaP (5 mg kg(-1) week(-1)), resveratrol (50 mg kg(-1) week(-1)) or BaP + resveratrol. Immunohistochemistry was performed on lung sections for the determination of CYP1A1 protein, BPDE-DNA adducts and apoptosis. A semi-quantitative immunohistochemistry score (H score) was used for data analysis. Mice exposed to BaP had a significant induction of lung BPDE-DNA adducts when compared with controls (H scores: control, 26, interquartile range 18-33; BaP, 276, interquartile range 269-288; P < 0.01). The BPDE-DNA adduct induction by BaP was abrogated significantly by resveratrol (H score: BaP + resveratrol, 103, interquartile range 96-113). A similar pattern was found by immunohistochemistry for apoptosis (H scores: control, 121, interquartile range 102-137; BaP, 288, interquartile range 282-292, P < 0.05; BaP + resveratrol, 132, interquartile range 121-141, P = NS) and CYP1A1 (H scores: control, 170.3, interquartile range 164-175; BaP, 302.3, interquartile range 291-315, P < 0.05; BaP + resveratrol, 200.7, interquartile range 174-215, P = NS). Western blotting confirmed that resveratrol prevented BaP-induced CYP1A1 expression. This increase in CYP1A1 expression in response to BaP administration most likely causes BaP metabolism, BPDE-DNA adduct formation and subsequent apoptosis. All BaP-induced effects could be prevented by resveratrol, suggesting a possible chemopreventive role for this natural phytoalexin against the development of lung cancer.

We conclude that our normal swim-up technique caused no more DNA damage to spermatozoa from normal semen samples than a direct swim-up technique that involved no centrifugation step.