Induction of sarcomas in rats by subcutaneous injection of dinitropyrenes

The carcinogenicities of potent mutagenic dinitropyrenes were examined by their subcutaneous injections into male F344/ DuCrj rats. Animals were injected with 0.2 mg each of 1,3- and 1,8-dinitropyrenes (1,3- and 1,8- DNPs ) dissolved in 0.2 ml of dimethyl sulfoxide (DMSO) twice a week for 10 weeks. In rats treated with 1,8-DNP, sarcomas were induced at the sites of injection in all 10 animals tested between the 113th and 127th experimental days. In rats treated with 1,3-DNP, 10 of 10 rats developed sarcomas between days 119 and 320. Some tumors induced by these chemicals were transplantable into the same strain of rats. No tumors developed in control rats, which received only DMSO.