Significance of sulfhydryl compounds in the manifestation of fluoroacetate toxicity to the rat, brush-tailed possum, woylie and western grey kangaroo.
Levels of citrate in kidneys and livers of rats with normal glutathione levels increased 6.8 and 1.7-fold respectively 2 h after dosing with 1.5 mg of compound 1080 (= 95% sodium fluoroacetate) per kilogram body weight. In animals with liver glutathione levels 15% of normal, increases in plasma and liver citrate levels after dosing with fluoroacetate were significantly greater than those of control animals. Cysteamine and N-acetylcysteine, like glutathione, partially protected aconitate hydratase from fluorocitrate inhibition in rat liver preparations but were unable to replace glutathione as a substrate for the defluorination of fluoroacetate in vitro. N-Acetylcysteine did not diminish plasma citrate levels of glutathione-deficient rats dosed with fluoroacetate, while cysteamine inhibited the rate of in vivo defluorination in glutathione-deficient brush-tailed possums. It is suggested that non-physiological sulfhydryl compounds are ineffective antidotes to fluoroacetate intoxication in vivo. The in vivo defluorination patterns of four mammal species with differing sensitivities to fluoroacetate did not indicate a direct relationship between tolerance and rate of defluorination and it is also suggested that a high level of activity of the glutathione-S-transferase responsible for the defluorination of fluoroacetate is not the major mechanism for circumventing fluoroacetate toxicity in resistant mammals.
D000818:Animals; D002951:Citrates / Q000378:metabolism*; D005463:Fluoroacetates / Q000633:toxicity*; D005978:Glutathione / Q000378:metabolism*; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D007614:Macropodidae / Q000378:metabolism*; D008297:Male; D008394:Marsupialia / Q000378:metabolism*; D009893:Opossums / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013045:Species Specificity; D013438:Sulfhydryl Compounds / Q000494:pharmacology*
D002951:Citrates; D005463:Fluoroacetates; D013438:Sulfhydryl Compounds; C014815:fluoroacetic acid; D005978:Glutathione