Morphology of oocyte and follicle destruction by polycyclic aromatic hydrocarbons in mice

The carcinogenic polycyclic aromatic hydrocarbons, benzo(a)pyrene, 3-methylcholanthrene, and 7,12-dimethylbenz(a)anthracene, destroy primordial oocytes in the mouse ovary. The rate of oocyte destruction was proportional to the activity of the ovarian microsomal cytochrome P-450-dependent monooxygenase, aryl hydrocarbon (benzo(a)pyrene) hydroxylase (EC 1.14.14.2) as well as to the carcinogenicity of the polycyclic hydrocarbon. After treatment with benzo(a)pyrene or 3-methylcholanthrene only primordial oocyte destruction occurred, and no evidence of toxicity was observed in surrounding granulosa or ovarian stromal cells. 7,12-Dimethylbenz(a)anthracene was much more toxic and destroyed large follicles and oocytes in addition to primordial oocytes and primary follicles. Seven weeks after treatment with 3-methylcholanthrene the ovary had the bland afollicular appearance characteristic of ovarian failure. These three polycyclic aromatic hydrocarbons are capable of producing premature ovarian failure in rodents.