Induction of sister-chromatid exchange in human lymphocytes by smoke condensates from different brands of cigarette

Abstract

(Accepted 10 June 1981) Cigarette-smoke condensate contains over 1200 chemical entities (Schmeltz et al., 1974), many of which are known or suspected carcinogens (Weisburger et al., 1977). The mutagenicity of cigarette-smoke condensate has been shown in several short- term test systems, e.g. in bacterial tests (Hutton and Hackney, 1975; Kier et al., 1974; Sato et al., 1977) and in cytogenetic assays (de Raat, 1979; Hopkin and Evans, 1979). However, it has become evident that the mutagenicity of the tar is not only due to polycyclic aromatic hydrocarbons (Hopkin and Perry, 1980; Mizusaki et al., 1977), but rather to other mutagenic agents, e.g. pyrolysis products of amino acids (Yoshida and Matsumoto, 1980). Thus, the content of tar in different brands of cigarette may not be the major variable determining the mutagenicity of different types of cigarette. In the present work, the mutagenic activity in different types of cigarette-smoke condensate was evaluated by using the sensitive sister-chromatid exchange (SCE) analysis in cultured human lymphocytes. The smoke condensates were made from 6 commercially available cigarette brands (Table 1) by using the Filtrona 302 smoking machine (Filtrona Int., Great Britain). Cambridge type cigarette holders were used, and the condensates were trapped on Cambridge glass-fibre filters, by using standard 2-sec 35-ml puffs once each 60 sec. The butt length depended on the length of the filter so that with filtered cigarettes (A, B, C) the butt length was 28 mm and with non-filter cigarettes (D, E, F) it was 23 mm. The tars were extracted with 60 ml cyclohexane (p.a., Merck AG), and each sample was evaporated to dryness in liquid nitrogen and dissolved (25.0 mg tar/ml) in dimethyl sulphoxide (DMSO, p.a. Fluka AG) (Table 1). Heparinized venous blood of one healthy male donor was used in the experiments. Whole-blood lymphocyte cultures, containing bromodeoxyuridine (BrdU, Calbiochem), 5.0 #g/ml, were established and harvested according to routine methods of the laboratory (Norppa et al., 1980). 0165-7992/82/0000-0000/$02.75 © Elsevier Biomedical Press