The carcinogenicity of intravenous nickel carbonyl in rats.

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.