Role of oxygen radicals scavenging enzymes in the protoporphyrin induced photohemolysis

Summary Inhibition of superoxide dismutase by diethyldithiocarbamate or cyanide increases the rate of red blood cells lysis after irradiation in the presence of protoporphyrin IX. Catalase activity, which is decreased during the photohemolytic process, appears to be not essential for the lytic event. No relationship between catalase activity and hemolysis rate was found. Superoxide dismutase appears to prevent only in part catalase inactivation by singlet oxygen.     

The effects of chronic peroxide intake on the peroxide metabolism enzyme activities of rat organs

In rats receiving a dilute aqueous solution of hydrogen peroxide for a prolonged period, the activity of the peroxide metabolising enzymes, i.e. superoxide dismutase, peroxidase and catalase, is significantly increased in most tissues.     

Effects of chronic caffeine feeding on the activities of oxygen free radical defense enzymes in the growing rat heart and liver

The purpose of the present study was to determine the relationship between concentration of Zn, Cu and Fe, and the catalase, glutathione peroxidase and superoxide dismutase activities in the heart and liver of newborn rats whose dams were fed a diet supplemented with caffeine. Heart Zn levels of the 22- and 30-day-old rats of the caffeine group showed a decrease, whereas liver Zn levels showed an increase compared to the control. Cu levels in the liver at day 22 in the caffeine group were less than in the control. Cu- and Zn-containing superoxide dismutase activities showed an increase in the hearts of the caffeine group compared to the control. The activity of catalase and glutathion peroxidase showed no difference in the heart and liver between the groups. The present study suggests the possible involvement of superoxide dismutase enzyme in the impairment of heart formation as a result of chronic caffeine intake in the early growing period.     

The effects of chronic peroxide intake on the peroxide metabolism enzyme activities of rat organs

Summary In rats receiving a dilute aqueous solution of hydrogen peroxide for a prolonged period, the activity of the peroxide metabolising enzymes, i.e. superoxide dismutase, peroxidase and catalase, is significantly increased in most tissues.Properties of enzymes. Serial publication, Part XV.     

Inhibition of erythrocyte ATPase activity by aclacinomycin and reverse effects of ascorbate on ATPase activity

We studied the effect of aclacinomycin on human erythrocyte membrane enzymes. Aclacinomycin inhibited ATPase, including Na-K-dependent ATPase, ouabain insensitive ATPase and Ca-ATPase. However acetylcholinesterase was not inhibited by aclacinomycin. The ATPase activities were not inhibited by aclacinomycin if ascorbate was added to the incubation mixture. However other reducing agents, alpha-tocopherol, superoxide dismutase and catalase had no effect on ATPase activity. Ascorbate may protect membrane proteins and lipids from peroxidate damage.     

Hemolysis and peroxidation in heavy metal-treated erythrocytes; GSH content and activities of some protecting enzymes

Summary The activities of superoxide dismutase, catalase and glutathione peroxidase, and the level of reduced glutathione, were measured in heavy metal-treated erythrocytes. The hemolytic metals were found to significantly deactivate both catalase and glutathione peroxidase and to decrease the level of reduced glutathione, thus providing suitable conditions for the development of peroxidation.     

Role of active oxygen species in diethyldithiocarbamate-induced gastric ulcer in the rat

Diethyldithiocarbamate, an inhibitor of Cu,Zn-superoxide dismutase, was recently found to be ulcerogenic in the rat stomach, and active oxygen species were found to be responsible for its ulcerogenicity. To clarify which active oxygen species play a role in ulcerogenesis, the effects of various scavengers and iron-chelators were studied. As superoxide dismutase and catalase reduced the ulcerogenesis induced by diethyldithiocarbamate, the superoxide radical and hydrogen peroxide were considered to play a pathogenic role in this ulcer model.     

Role of active oxygen species in diethyldithiocarbamate-induced gastric ulcer in the rat

Summary Diethyldithiocarbamate, an inhibitor of Cu,Zn-superoxide dismutase, was recently found to be ulcerogenic in the rat stomach, and active oxygen species were found to be responsible for its ulcerogenicity. To clarify which active oxygen species play a role in ulcerogenesis, the effects of various scavengers and iron-chelators were studied. As superoxide dismutase and catalase reduced the ulcerogenesis induced by diethyldithiocarbamate, the superoxide radical and hydrogen peroxide were considered to play a pathogenic role in this ulcer model.     

Glutathione peroxidase, superoxide dismutase and catalase in the red blood cells of GSH-normal and GSH-deficient sheep

Levels of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase were measured in the red blood cells of glutathione(GSH)-normal and GSH-deficient sheep. There were no significant differences in any of the 3 enzyme activities measured in the 2 groups of sheep. Also, there was no relationship between GSH level and the enzyme activity. These results suggest that inspite of large differences in GSH levels, the red blood cells from GSH-normal and GSH-deficient Merino sheep appear to have similar response to oxidative stress against which GSH is credited to play a major role.     

Role of some oxidative enzymes in root nodules ofTrigonella foenum-graecum

Cellular and Molecular Life Sciences - Levels of superoxide dismutase and peroxidase were found to be lower and that of catalase higher in the nodule cytosol and bacteroids as compared to roots....     

Methaemoglobinbildung durch Röntgenstrahlen in normalen und katalasefreien Erythrocyten des Menschen

Summary Methaemoglobin-formation in irradiated human red cells largely depends on catalase activity in either phase of the system. The formation rate is low in normal, but high in acatalatic cells. The latter rate can be lowered to normal by adding 0.1 /ml catalase to the suspending medium.     

The endothelium-dependent relaxation of human middle cerebral artery: effects of activated neutrophils.

Neutrophils, activated by 4 beta-phorbol-12 beta-myristate-13 alpha-acetate, decreased acetylcholine-induced relaxation of strips of human middle cerebral artery precontracted with noradrenaline. This effect was prevented by catalase, but not by superoxide dismutase. Nifedipine, propranolol and, less markedly, captopril reduced the decrease in acetylcholine-induced relaxation. Aspirin and dipyridamole did not reduce it.     

Respiratory burst in peritoneal exudate cells in response to a modified tuftsin.

Intraperitoneal administration of tuftsin-M [Thr-Lys-Pro-Arg-NH-(CH2)2-NH-CO-C15H31] to Balb/C mice has been shown to induce a respiratory burst in the peritoneal exudate cells. The macrophages exhibited enhanced levels of O2-, H2O2, NADPH oxidase and myeloperoxidase, but the activities of superoxide dismutase, catalase and glutathione peroxidase remained virtually unchanged. The magnitude of the oxidative burst depended directly on the dose of tuftsin-M; higher activity was observed at higher doses of the peptide. Tuftsin-M enhanced the generation of both O2- and H2O2 under in vitro conditions, as did phorbol myristate acetate. These results suggest that tuftsin-M could enhance non-specific defence against infections by activating the macrophages.     

Superoxide anion scavenging effect and superoxide dismutase activity of Ginkgo biloba extract

Ginkgo biloba extract is known to be efficient in diseases associated with free radical generation. The purpose of this work was to study, under in vitro conditions, the action of Ginkgo biloba extract (Gbe) against superoxide anion (O2-.), which is directly or indirectly implicated in cell damage. Gbe appears to have both an O2-. scavenging effect and also a superoxide dismutase activity. Its antiradical effect was demonstrated by low temperature electron spin resonance and in a non-enzymatic system (phenazine methosulfate-NADH), and its enzymatic activity was shown by polarographic determination.     

Effects of scavengers of superoxide radicals, hydrogen peroxide, singlet oxygen and hydroxyl radicals on malondialdehyde generation from arachidonic acid by bovine seminal vesicle microsomes

Superoxide dismutase, catalase and sodium formate did not inhibit the formation of malondialdehyde (MDA) from arachidonic acid, suggesting that O2-., H2O2 and OH. are not involved in the enzymatical oxidation of arachidonic acid. Sodium azide was found to be an inhibitor of MDA production.     

Superoxide dismutase activity in the Spanish population

Superoxide dismutase is an enzyme that catalyzes the dismutation of superoxide radicals to hydrogen peroxide and molecular oxygen. This superoxide radical is produced by all aerobic cells as a normal metabolic intermediate of molecular oxygen, and is dangerous for the cell because it induces the inactivation of various enzymes, lipid peroxidation and mutations. Superoxide dismutase can therefore be considered as a protective enzyme. The purpose of this work was to determine the level of superoxide dismutase activity in the Spanish population, and to study the factors that influence this activity. The superoxide dismutase activity of 2397 individuals was determined using the method described by Minami and Yoshikawa. The superoxide dismutase activity level in the adult Spanish population was found to be 4.16 +/- 0.89 Units/ml of blood. No significant variations with respect to sex were detected. But it was observed that the superoxide dismutase activity level was 9% higher in the young urban Spanish population.     

Superoxide dismutase activity in the Spanish population

Summary Superoxide dismutase is an enzyme that catalyzes the dismutation of superoxide radicals to hydrogen peroxide and molecular oxygen. This superoxide radical is produced by all aerobic cells as a normal metabolic intermediate of molecular oxygen, and is dangerous for the cell because it induces the inactivation of various enzymes, lipid peroxidation and mutations. Superoxide dismutase can therefore be considered as a protective enzyme. The purpose of this work was to determine the level of superoxide dismutase activity in the Spanish population, and to study the factors that influence this activity. The superoxide dismutase activity of 2397 individuals was determined using the method described by Minami and Yoshikawa. The superoxide dismutase activity level in the adult Spanish population was found to be 4.16±0.89 Units/ml of blood. No significant variations with respect to sex were detected. But it was observed that the superoxide dismutase activity level was 9% higher in the young urban Spanish population.     

Über Pflanzenwachstumsregulatoren

Summary Simazin inhibits the Hill reaction, i.e. the use of light energy for the synthesis of energy-rich compounds. Isolated maize (corn) and spinach chloroplasts are, when analyzed in the Hill reaction, equally sensitive to the inhibitory action of Simazin. Furthermore, it does not influence the activity of catalase, nor does it inhibit respiration.Competitive inhibition of DPN is not seen in the presence of Simazin. On the other hand, this compound appears to interfere directly with the intermediate steps needing chlorophyll.     

Ferredoxin reductase catalyzes styrene oxidation to styrene oxide

Summary The flavoprotein ferredoxin reductase catalyzed the oxidation of styrene to styrene oxide in the presence of NADPH. This reaction was inhibited by the addition of catalase and superoxide dismutase. The addition of the nonheme iron protein ferredoxin partially inhibited styrene oxidation. H₂O₂ was also able to catalyze this reaction when added to the enzyme in the absence of NADPH.Acknowledgments. This work was supported by C.N.R. (National Research Council), Rome, Italy contract No. 79.03197.04.