- Comparative gastrointestinal enzyme activity and activation of the promutagen 2,6-dinitrotoluene in male CD-1 mice and male Fischer 344 rats. Chadwick, R.W., George, S.E., Chang, J., Kohan, M.J., Dekker, J.P., Long, J.E., Duffy, M.C. Cancer Lett. (1990)