Oral N-acetylcysteine has a deleterious effect in acute iron intoxication in rats.

Acute iron intoxication is associated with depletion of reduced glutathione in hepatocytes and changes in the glutathione system enzymes. We hypothesized that treatment with N-acetylcysteine (NAC), a glutathione reducing agent and an antioxidant, would reduce mortality in acute iron intoxication. We used a rat model to test this hypothesis. Male rats were assigned to 4 groups. Group 1 received 400 mg/kg elemental iron by oral gavage, group 2 received the same dose of iron followed by NAC, group 3 received NAC only, whereas group 4 received distilled water. Iron and liver transaminases in the blood, and glutathione system enzymes in the liver and erythrocytes were measured. Mortality in group 2 was significantly higher after 2, 6, and 24 hours compared with group 1 (P < .001). No deaths were observed in groups 3 and 4. Serum iron levels were significantly higher in group 2 rats compared to group 1 rats (P < .001). Hepatic and erythrocyte glutathione system enzymes were significantly lower among rats in group 2 compared to rats in group 1. The administration of NAC probably increased the absorption of iron through the gastrointestinal tract, causing higher serum iron levels with significant hepatic damage. These results indicate that in a rat model of acute iron intoxication, orally administered NAC may increase mortality.

Depletion of glutathione system enzymes of the liver and erythrocytes in a rat model of acute iron poisoning.

ABSTRACT The proposed mechanism of iron-induced hepatotoxicity is free radical formation. It was hypothesized that the glutathione system of the liver and erythrocytes will be affected by acute iron poisoning. Male Wistar rats, 6-8 weeks of age, were assigned to one of three groups. Group I received distilled water, group II received 400 mg/kg elemental iron, and group III received 750 mg/kg elemental iron. All groups were gavage fed. Iron concentration, glutathione, and glutathione system enzymes were then measured in the liver and erythrocytes. The hepatic level of reduced glutathione (GSH) was significantly lower in groups II (3.1 +/- 4.6 mumol/mg protein) and III (4.7 +/- 4.6 mumol/mg protein) in comparison with group I (11.5 +/- 6.2 mumol/mg protein) (p < 0.001). Hepatic levels of glutathione S-transferase (GST) were higher and glutathione peroxidase (GPX) levels were lower in group III compared to groups II and I (p < 0.001 and p < 0.001). Compared to group I, glutathione reductase (GR) was lower in groups II and III (p < 0.001). There was no correlation between GSH, oxidized glutathione (GSSG), GST, GR, and GPX levels in the erythrocytes and in the liver (p = 0.41, p = 0.48, p = 0.49, p = 0.53, p = 01.4, and p = 0.84, respectively). In conclusion, acute iron intoxication in rats is associated with depletion of reduced glutathione in the liver.