• Toxicological Research
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• v.12 no.2
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• pp.289-293
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• 1996

Our previous studies demonstrated that quinone (menadione) is cytotoxic to rat platelets. In an attempt to assess the relative contributions of redox cycling and/or arylation in quinone-induced cytotoxicity, we have studied three quinones with different mechanisms: 2, 3-dimethoxy-1, 4-naphthoquinone (DMNQ; pure redox cycler), menadione (both redox cycler and arylator), and 1, 4-benzoquinone (pure arylator). The order of redox cycling capacity in platelet rich plasma (PRP) isolated from rats was menadione>DMNQ>1, 4-benzoquonone, which was consistent with the previous studies using isolated hepatocytes. 1, 4-Benzoquinone was more toxic to rat platelets than menadione, while DMNQ did not cause cell death at all. Lactate dehydrogenase inhibition studies revealed that 1, 4-benzoquinone inhibited significantly in a time-dependent manner, while menadione and DMNQ did not at all. These results suggested that arylation by quinone compounds might play a critical role in quinone-induced cytotoxicity in rat platelets.