The carcinogenicity of i.v. nickel carbonyl, Ni(CO)4, was tested in Sprague-Dawley rats. In 72 rats (Group A) that survived a single 50% lethal dose injection of Ni(CO)4 (2.2 mg nickel per 100 g), the incidence of malignant tumors (8.3%) was not significantly greater than the incidence in 47 rats in the control group (4.3%). In 121 rats (Group B) that survived six 5% lethal dose injections of Ni(CO)4 (0.9 mg nickel per 100 g) at intervals of 2 or 4 weeks, the incidence of malignant tumors (15.7%) was significantly greater than in the controls (p < 0.05). The 19 malignant tumors in Group B included 6 undifferentiated sarcomas (lung, pleura, liver, pancreas, uterus, and abdominal wall), 3 fibrosarcomas (neck, pinna, and orbit), 3 carcinomas (liver, kidney, and breast), 1 s.c. hemangioendothelioma, 1 leukemia, and 5 lymphomas (lung). This study demonstrates that multiple parenteral injections of Ni(CO)4 can induce diverse malignant tumors in varied organs and tissues of the rat.
Sponsored by United States Atomic Energy Commission Grant AT(11-1)-3140; by USPHS Grant CA-11250 from the National Cancer Institute; and by United States Environmental Protection Agency Contract EHS-C-71-109.