In vivo effects of paraquat on some oxidative enzymes of mice

The effect of paraquat lung on mononuclear cells

The mouse footpad swelling test was used to clarify the possibility of the induction of local cellular reaction with cell suspension of mouse lungs treated with paraquat in a syngeneous animal. Among the inbred strains used, the highest, statistically significant cellular reactivity was observed in C3H/He strain mice. These results suggest indirect evidence of macrophage activation in the lung toxicity of paraquat.

Paraquat as an agent affecting antioxidant enzymes of common carp erythrocytes

The effects of paraquat on the superoxide dismutase, catalase, glutathionine peroxidase activities and lipid peroxidation at different times of paraquat exposure of Cyprinus carpio morph L. erythrocytes were studied. Typical characteristics were observed in the changes of the enzyme activities of the erythrocytes after exposure to paraquat. The haemoglobin concentration of common carp haemolysates was decreased by exposure to paraquat.

Effects of various thiols on paraquat toxicity

It was demonstrated that cysteine and D-penicillamine are able to replace reduced glutathione to some extent in the glutathione peroxidase reaction. An in vivo study was made of the role played by--SH compounds in the antioxidant enzyme system involved in the detoxication of the LD50 of paraquat (PQ), and hence of their role in the detoxication of PQ. The effectiveness was D-PA greater than GSH greater then Cys in the liver and GSH greater than Cys greater than D-PA in the lung.

Effects of paraquat on peroxide metabolism enzymes and lipid peroxidation in the rat

Investigation has been made of how the LD50 and LD100 of PQ influence the peroxide metabolism enzymes and lipid peroxidation in organ homogenates and blood samples of the rat. The peroxide metabolism enzyme activities were changed in a concentration dependent manner. In general, the effect of the lower doses of PQ on the superoxide dismutase, catalase activities and lipid peroxidation are increased. The glutathione peroxidase activity was decreased. Higher doses of PQ enhanced all of enzyme activities and lipid peroxidation studied.

Study of the effects of paraquat on the peroxide metabolism enzymes in guinea-pig

1. Guinea-pigs, which exhibit a similar metabolism to that of man insofar as they are incapable of synthesizing ascorbic acid, were poisoned with Gramoxon containing the LD50 or LD100 of paraquat. 2. A study was made of how the paraquat poisoning affected previously investigated tissue parameters, the superoxide dismutase, catalase and glutathione peroxidase activities and the lipid peroxidation. 3. In accordance with earlier results, the paraquat influences these parameters in different ways in all the tissues examined, depending on its concentration. 4. These parameters comprise primarily affected systems as regards paraquat toxicity.

Some new data to the toxicological effects of paraquat and the therapy

1. Substances previously tested therapeutically were studied to obtain evidence on the pathomechanism in mice of paraquat, the active ingredient of Gramoxon, connected with the radicals formed from molecular oxygen, and also to extend the therapeutic possibilities. 2. The effects of these substances were assessed on the basis of the 72-hr survival rate and the percentage ratio of the wet lung weight to the overall body weight. 3. Other toxicological parameters too were followed. 4. Our present investigations indicate that, in agreement with our earlier results, besides reduced glutathione and ascorbic acid, vitamin E and C-ase are of the greatest importance from the aspect of the protection against paraquat toxicity. 5. In addition to those listed, other materials too, e.g. antifibrotic substances, naturally possess considerable detoxicating properties too.