title: The effect of high concentrations of oxygen on paraquat and diquat toxicity in rats.
abstract: High concentrations of oxygen are known to enhance the toxic effects of paraquat in the lung. We have examined the effects of paraquat (2.5 mg/kg or 20 mg/kg subcutaneously) and diquat (10 mg/kg or 20 mg/kg subcutaneously) on mortality and lung pathology in rats exposed to air or to an atmosphere of 85% oxygen. Our results show a 10-fold increase in mortality when paraquat is given to rats placed in 85% oxygen rather than air, but only a 2-fold increase in the lethality of diquat. Lung damage typical of early paraquat intoxication is seen following 20 mg/kg paraquat in air or oxygen, with damage to type I and type II alveolar cells. Selective damage to the type II cell is produced by lower levels of paraquat (2.5 mg/kg) and by 20 mg/kg diquat, both in 85% oxygen, other cell types showed little change. Lung damage is minimal following 2.5 mg/kg paraquat or 20 mg/kg diquat in air, or exposure to 85% oxygen alone. It is suggested that the type II cell may be the primary target cell for paraquat and diquat in the lung.
mesh_terms: D000818:Animals; D004178:Diquat / Q000633:toxicity*; D004347:Drug Interactions; D008168:Lung / Q000648:ultrastructure; D010100:Oxygen / Q000494:pharmacology*; D010269:Paraquat / Q000633:toxicity*; D011726:Pyridinium Compounds / Q000633:toxicity*; D051381:Rats
chemical_list: D011726:Pyridinium Compounds; D004178:Diquat; D010269:Paraquat; D010100:Oxygen