Complement synthesis by guinea pig peritoneal macrophages: failure to detect chemical carcinogens

In vitro production of the second and fourth components of complement (C2 and C4, respectively) by peritoneal macrophages from noninbred Hartley guinea pigs was tested after the animals had been inoculated with known carcinogens. The system demonstrated the capacity of N-nitrosodimethylamine to decrease C2 and C4 production. However, a similar decrease in C2 and C4 production was seen with only CCl4, 1 of the 10 chemical carcinogens studied. This system had little usefulness as a short-term screening procedure for the detection of carcinogenicity. The effect of the carcinogens on several other functions of peritoneal macrophages was also determined. The number of peritoneal exudate cells (PEC) was significantly lower in carcinogen-inoculated animals than in solvent-inoculated controls for three carcinogens: BeSO4, P < 0.005; CHCl3, P < 0.025; and CCl4, P < 0.01. However, the capacity of the PEC to adhere to plastic was decreased by only CHCl3 (P < 0.05), and adherent cells from all guinea pigs produced normal amounts of total secreted protein.