The lack of effect of 7,12-dimethylbenz(a)anthracene on the endocrine function of the gonads.

Since the report by Yang et al. (11) that carcinogenic polynuclear aromatic hydrocarbons as a group bear steric resemblances to steroid hormones, there has been considerable interest in the effect of these compounds on the adrenals, gonads, and pituitary. Huggins and Morii (5) found that DMBA induced adrenal ne crosis and hemorrhage when fed to adult rats. There have been conflicting reports on the effect of DMBA on the gonads. Wong et al. (10) showed that DMBA, when fed to young adult female rats, was not only capable of inducing acute adrenal ne crosis, but in half the animals also caused necrosis of the corpora lutea. On the other hand, Ford and Huggins (4) could find no abnormality in the ovaries of rats given a single i.V. injection of DMBA. They also noted that DMBA caused damage to the testis, but lesions were confined to cells that actively synthesize DNA, i.e., spermatogonia and resting spermatocytes. Stern et al. (8) reported the initiation of vaginal cycling in androgen-sterile rats within 24-72 hr of DMBA administration. Since DMBA also augmented lactogenesis in these animals, the vaginal changes were thought to be secondary to prolactin re lease. A decrease in the weights of the pituitary gland, the ovaries, and the uterus of carcinogen-treated rats was also found. The purpose of the present paper is to investigate the direct effect of DMBA on the gonads. Two methods have been em ployed. HCG has been used to stimulate steroidogenesis in rat ovaries and testes. Weight changes in the accessory reproduc-