Metabolic consequences of dietary 2,3-dichloro-1,4-naphthoquinone (CNQ) in the rat. Alteration in anti-oxidant enzyme activities.

Dietary exposure of rats to a high concentration of 2,3-dichloro-1,4-naphthoquinone (CNQ) (2 g/kg diet) for 60 days altered cardiac mitochondrial function and activities of anti-oxidant enzymes in hepatic and cardiac tissue. CNQ moderately depressed the cardiac mitochondrial respiratory control ratio (RCR) to 85% of control; this was exacerbated to 60% of control in animals fed alpha-tocopherol-deficient diets. Dietary CNQ increased hepatic superoxide dismutase (SOD) and catalase activities and increased cardiac SOD activity, but depressed cardiac glutathione reductase and hepatic glutathione peroxidase activities. These effects are consistent with previous in vitro findings that CNQ induces oxidative stress. No significant differences in heart weight or body weight were observed in rats fed CNQ as compared to untreated controls.