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The activities of the antioxidant enzymes and lipid peroxidation were compared in the red blood cells from the blood of 50 mothers and the umbilical cord of 50 full-term healthy neonates. The antioxidant activities (except that of catalase) and the lipid peroxidation were found to be higher in the cord blood. These observations differed from the previous literature data: a parallel could be found only with the concept (connected with oxygen radicals) of the early closure of the ductus arteriosus.

The activities of superoxide dismutase and catalase in livers of fish and other Antarctic vertebrates were examined. Significant differences between superoxide dismutase activities in livers of white-blooded and red-blooded fish species were observed. Superoxide dismutase seems to be involved more than catalase in protection processes against cell damage caused by oxygen free radicals.

1. We have studied and compared the peroxide metabolism enzymes (SOD, P and C) of the main organs of fresh-water mollusc, chicken, mouse, guinea-pig, rabbit, cat and dog. 2. The liver exhibited the highest SOD activity. The enzymatic activities of the organ homogenates of the guinea-pig stand out in comparison with the values for the other homogenates examined. 3. The liver, kidney and total brain homogenates of the chicken and the vertebrates display no, or only a very low P activity. The highest P activities were measured in the haemolysates. 4. The C and SOD values exhibit a certain parallelism. 5. The peroxide metabolism enzyme activities calculated by utilizing the protein measurements permit the establishment of a more realistic enzymatic activity.

In the liver of neonate rats and in tissues of adult rats a study was made of the effect of D-penicillamine treatment in vivo on the enzymes of peroxide metabolism, lipid peroxidation and other components. It was found that D-penicillamine primarily acts by decreasing lipid peroxidation, thus stabilizing the membrane.

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.

The effects of a 7-day treatment with Haloperidol or reserpine (in both cases 0.1 mg/kg per day) were studied on the superoxide dismutase and catalase activities and the lipid peroxidation in various discrete regions of the rat brain. It was found that these neuroleptics change the lipid peroxidation and the activities of the enzymes in similar directions in the brain areas tested.

Comparative studies were made of the activities of Cu,Zn-superoxide dismutase, Mn-superoxide dismutase, catalase and glutathione peroxidase in organ homogenates from two herbivorous (grass carp and silver carp) and three omnivorous fish (barbel, crucian carp and common carp). The protein contents and lipid peroxidation of the organ homogenates were also compared. These comparative measurements provided control values for subsequent toxicological examinations. For the herbivorous fish, the highest total superoxide dismutase activity was observed in the kidney, followed in turn by the liver or spleen. In contrast, the highest total superoxide dismutase activity in the barbel was found in the roe, in the crucian carp in the liver, and in the common carp in the liver too. The quantitative distributions of the two peroxide metabolism enzymes glutathione peroxidase and catalase in the organ homogenates present very varied pictures. The results of the lipid peroxidation are similarly difficult to fit into one framework, even for fish following the same diet. It appears that the enzyme activities mentioned in points 4 and 5, together with the lipid peroxidation, depend not on the species, but on the variety.

A study was made of the changes in the activities of the antioxidant enzymes superoxide dismutase and catalase in the blood of chronic uraemic patients before and after haemodialysis. Changes in serum lipids (primarily neutral lipids), lipoproteins and lipid peroxidation were also followed. Before haemodialysis, antioxidant enzyme activities decreased, while lipid peroxidation increased both in the plasma and in the RBC haemolysates. Quantitative changes in the lipids increased the risk factors. Haemodialysis moderated these risk factors and a tendency to improvement was observed.

1. A study was made of the SOD, P and C activities and the protein contents of the tissue homogenates in the five most important organs of six inbred mouse strains. 2. From the results of comparative examinations it emerges that the above PME's exhibit substantial differences in the various inbred mouse strains. 3. Accordingly, only pure inbred mice or rats raised under identical conditions can be used for PME comparisons. 4. The examinations also reveal that the PME levels of the inbred strains are genetically determined.

The radical produced aerobically in the glucose oxidase reaction reduces the oxidated cytochrome c. The extent of reduction depends on the concentrations of substrate (glucose) and enzyme. Superoxide dismutase purified from various sources does not inhibit the cytochrome c reduction, but catalase does, in proportion to its concentration. This inhibition, which might be utilized for quantitative catalase determinations, provides further evidence for the formation of H2O2 in the glucose oxidase reaction.

The effects of paraquat, the active ingredient of Gramoxone, were studied on frogs (Rana esculenta) kept at 4 degrees C or 20 degrees C, to establish its effects on the survival, the antioxidant enzyme system and the lipid peroxidation of the tissues (liver and lung). The lower temperature was found to increase the survival. The activities of the antioxidant enzymes were decreased or not influenced by the LD50 of paraquat at the lower temperature, whereas the LD100 often resulted in a significant enzymatic activity increase. It was an important finding that the lipid peroxidation of the lipid decreased in response to paraquat at 4 degrees C, but increased at 20 degrees C. The lipid peroxidation of the lung increased at both temperatures.