Effect of carcinogenic components of cigarette smoke on in vivo production of murine interferon.

Mice were treated with several different potentially carcinogenic components of tobacco smoke. The chemicals used were: 4-aminobiphenyl and aniline-HCl, which are found in high concentrations in sidestream tobacco smoke; hydrazine sulfate, which is found in high concentrations in mainstream tobacco smoke; and 2-methylquinoline, which is found in intermediate concentrations in both sidestream and mainstream smoke. The chemicals were injected i.p. into mice, and then alpha/beta interferon was induced in the mice by i.v. injection of polyriboinosinic-polyribocytidylic acid. The interferon was induced either 2, 24, or 48 hr after treatment with the tobacco smoke components. Mice treated with 4-aminobiphenyl showed some depression of interferon production 2 hr after treatment, maximum inhibition of interferon induction 24 hr after treatment, and a return to control levels of interferon 48 hr after treatment. Mice treated with hydrazine sulfate showed maximum inhibition of interferon induction 24 hr after treatment but no effects at any other treatment time. These components were the most carcinogenic chemicals of those utilized in this study. Treatment of mice with aniline-HCl, a chemical whose carcinogenic potential is still debated, resulted in marginal depression of interferon induction 24 hr after treatment. 2-Methylquinoline, the chemical with the lowest carcinogenic potential in this study, had no effect on interferon induction after administration to mice. In vivo interferon induction was, therefore, inhibited by treatment of mice with chemical carcinogens found in tobacco smoke. The efficacy of the chemical in inhibiting interferon induction was not influenced by the mainstream or sidestream smoke predominance of the chemical.