Mechanisms of DNA damage induced in rat hepatocytes by quinones.

Hydroquinone (HQ), catechol (CAT), duroquinone (DQ) and resorcinol (RES) have been shown to induce single-strand breaks (SSB) in DNA in isolated hepatocytes using the alkaline elution assay. The relative capacities of these agents to induce SSB were shown to be: DQ = HQ much greater than CAT greater than RES. Preincubation of hepatocytes with the Ca(2+)-chelator Quin-2 AM reduced the level of DNA damage to a great extent, as did treatment with DQ and RES, and, to a lesser extent, treatment with HQ and CAT. Preincubation with an inhibitor of poly(ADP-ribose) polymerase, 3-amino-benzamide, did not influence the extent of DNA damage caused by DQ and RES, but increased the damage caused by HQ and CAT. The conclusion of the present investigation was that the dominating reaction of HQ and CAT, with DNA is an arylation, whereas DQ and RES induce DNA damage by oxidative stress.