Further studies of lipid peroxidation in human paraquat poisoning.

In patients with subacute toxic reactions from paraquat poisoning (death within 11 to 41 days), the extent of lipid peroxidation, expressed as serum malondialdehyde level, was 2.7-fold higher (12.33 +/- 4.42 nmole/mL) before pulmonary fibrosis than that in normal controls (4.55 +/- 1.23 nmole/mL). The extent of lipid peroxidation in patients with acute toxic reactions (death within one to three days) was not elevated; these patients died of pulmonary edema and hemorrhage (acute respiratory distress), liver failure, renal failure, and adrenal necrosis. Remarkable high levels of paraquat (greater than 5 mg/L) were found in the urine, serum, and tissues of patients with acute toxic reactions; a small amount of paraquat was found in the serum or urine of patients with subacute toxic reactions five to 11 days after ingestion. Patients who survived had no elevation in lipid peroxidation. Administration of vitamin E (100 to 4,000 mg/day from the first hospital day) had no effect on survival.