MUTAGENS OF POTENTIAL SIGNIFICANCE 199 



open field for the manufacturers, since advertising and sales pro- 

 motion can be aimed right at the general public. But since most use of 

 vitamins is superfluous, even slight evidence of mutagenicity should 

 cast doubt upon their continued indiscriminate use. 



Contraceptive jellies and creams have to be considered, because al- 

 though the exposure is intermittent, it is widespread. A very large num- 

 ber of compounds are used for direct contact contraception of this kind. 

 If the contraception is effective, there is no immediate genetic hazard, 

 but, as you know, the incidence of failure in contraception is consider- 

 able. I wonder about a sperm which has managed to get through this 

 deleterious environment and fertilize an egg. Do we have something 

 here analogous to the elegant little technique in Drosophila of causing 

 mutations with vaginal douches and sperm baths? The kinds of com- 

 pounds used for human contraception are principally detergents (both 

 anionic and cationic) , a variety of organic acids, phenyl mercuric com- 

 pounds, and quinolines (17). Such compounds could possibly be tested 

 under comparable conditions for mutagenic effect. 



In the case of phenyl mercuric compounds, small amounts may be 

 absorbed from the vaginal site into the general circulation. 



An effective oral contraceptive has now been introduced for general 

 use, approved by the Food and Drug Administration on the basis of its 

 nontoxicity, and already administered to many thousands of women. 

 Naturally, no thought has been given to potential mutagenicity. This 

 is a progesterone-like compound known as norethynodrel, and by the 

 trade name Enovid (48) . Its structure is shown in Figure 26, where it 

 is compared with the natural hormones progesterone and estradiol. 

 There is no methyl group in the 19 position, where progesterone does 

 have a methyl group, so this is termed a 19-norprogestational com- 

 pound. 



Norethynodrel acts by suppressing ovulation, much as progesterone 

 itself ordinarily does during pregnancy. It is administered at 10 mg 

 daily from the fifth to the twenty-fifth menstrual day; in other words, 

 women are exposed almost continuously to this particular steroid. 



Since some steroids at least have been shown to be mitotic poisons in 

 plant cells (5), the effects of this particular one upon the genetic 

 apparatus should be studied. Certainly we can anticipate that this 

 compound, or others like it, will eventually be used on a nearly uni- 

 versal scale. On the other hand, for reasons suggested earlier, chemical 

 mutagens (at least those acting exclusively on dividing cells) may 

 present no great hazard to adult women. 



Finally, in Category III, a very special position is occupied by 



