The effect of benzo(a)pyrene on murine ovarian and corpora lutea volumes.

Objective: Women who smoke have impaired fertility and experience menopause at an earlier age. This experiment determined the effect of benzo(a)pyrene, a polycyclic aromatic hydrocarbon contained in cigarette smoke, on murine ovarian volume, total corpora lutea volume, individual corpora lutea volumes, and corpora lutea numbers.
Study Design: C57BL/6N mice were treated with intraperitoneal injections of 0 to 500 mg/kg benzo(a)pyrene in corn oil. The 20 mice at each dose were divided into four groups of five each and were killed at 1, 2, 3, or 4 weeks after treatment. Ovaries were serially sectioned and analyzed morphometrically.
Results: Benzo(a)pyrene produced a dose- and time-dependent decrease in ovarian volume, total corpora lutea volume, and number of corpora lutea per ovary. This effect was transitory at low doses with complete recovery of corpora lutea by 4 weeks. Compensatory hypertrophy of the individual corpora lutea occurred during the recovery phase. Ovarian function did not return in animals treated with the two highest doses.
Conclusion: Benzo(a)pyrene is a murine ovarian toxicant that inhibits corpus luteum formation in a dose- and time-dependent fashion.