EFFECT OF DIETARY PARAQUAT ON A RAT MUTANT UNABLE TO SYNTHESIZE ASCORBIC-ACID

To obtain some insight into the toxicity of paraquat (PQ) in humans, P Q dichloride at 250 ppm in the diet was administered to both normal (N O) rats and ODS-od/od (OD) rats which are unable to synthesize ascorbi c acid (AsA). Firstly, OD rats and NO rats treated with PQ were compar ed with untreated NO rats (GO). Only OD rats displayed several symptom s of PQ poisoning such as anorexia, hypokinesia, diarrhea, epistaxis, tremor and their pill became rough about 9 days after. Their cysteine proteinase inhibitor level in plasma and lung increased to 2- and 6-fo ld, respectively, of CO. In contrast, NO rats treated with PQ resemble d CO rats, and their cysteine proteinase inhibitor levels were unchang ed until 11 days. After this period they began to display symptoms. Se condly, OD rats fed with different amounts of AsA were compared. Exces s AsA delayed the onset of symptoms by only 1 day. Thirdly, the day of onset of symptoms was found to be influenced with the weight of rats.