In vitro induction of sister-chromatid exchanges after G0 exposure of human lymphocytes to five naphthofurans.

The induction of sister-chromatid exchanges (SCE) was studied in cultured human lymphocytes of two donors treated in G0 by five naphthofurans. The results showed that 2-nitro-7-methoxynaphtho(2,1-b)furan and 2-nitro-8-methoxy-naphtho(2,1-b)furan were very potent inducers of SCE, 2-nitronaphtho(2,1-b)furan was moderately active, while 2-nitro-7-bromonaphtho(2,1-b)furan and 7-methoxynaphtho(2,1-b)furan did not induce any SCE. These data corroborate the mutagenic, clastogenic and carcinogenic activities already evaluated in other in vitro and in vivo assays. They also show that some naphthofurans, but not all, are able to induce long-lived DNA lesions, like most alkylating agents.