Effects of D-penicillamine on some oxidative enzymes of rat organs in vivo

Summary 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.Properties of enzymes. Serial publication Part XVI.Acknowledgment. We should like to take the opportunity to express our thanks to the Directorate of Knoll AG, Ludwigshafen. FRG, for the kind gift of Metalcaptase^®.     

Digestive enzymes of some earthworms

Summary 4 species of tropical earthworms differed with regard to enzyme activity. The maximum activity of protease and of cellulase occurred in the posterior region of the gut of the earthworms. On the averageOctochaetona surensis shows maximum activity andDrawida calebi shows minimum activity for all the enzymes studied.     

Photoregulation of some enzymes fromNeurospora crassa

Summary Light-grown cultures ofNeurospora crassa showed photoregulation of a number of enzymes. Proteases and cytosolic malate dehydrogenase showed an increase in activity. There was a decrease in the activity of mitochondrial malate dehydrogenase, isocitrate dehydrogenase and cytosolic glucose-6P-dehydrogenase, isocitrate dehydrogenase and isocitrate lyase.     

Fungi on the surface of legume root nodules and phosphate solubilization

Zusammenfassung Es wird nachgewiesen, dass an den Wurzelknöllchen von Leguminosen Schimmelpilze vorkommen, die Calciumphosphat abbauen und offenbar die Bildung der Wurzelknötchen selber fördern.     

Photoregulation of some enzymes from Neurospora crassa

Light-grown cultures of Neurospora crassa showed photoregulation of a number of enzymes. Proteases and cytosolic malate dehydrogenase showed an increase in activity. There was a decrease in the activity of mitochondrial malate dehydrogenase, isocitrate dehydrogenase and cytosolic glucose-6P-dehydrogenase, isocitrate dehydrogenase and isocitrate lyase.     

Activity of some enzymes in experimental hypertension in the rabbit

Zusammenfassung Bei durch Nierenarterien-Drosselung nach kontralateraler Nephrektomie chronisch hypertonischen Kaninchen wird mit Antirenin regelmässig eine bestimmte hypotensive Wirkung erzeugt. Auffallend niedrige Reninblutwerte, stark herabgesetzte Monoaminoxydase-Aktivität und deutlich gesteigerte Dopadecarboxylase-Aktivität sind charakteristisch. Der Befund zeigt die Bedeutung der Niere in der Erzeugung der Blutdruckamine im Laufe einer chronischen Hypertonie.

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This investigation was aided in part by grants from the Office of the Surgeon General, United States Army (no. DA-49-007-MD-429), and from the National Health Institute, United States Public Health Service (no. H-444 (C 10)).     

Biochemical changes in some acrosomal enzymes of spermatozoa during maturation

Summary Goat spermatozoal hyaluronidase and acrosin show significantly increased activities during transition from caput to cauda epididymis. The activity of alkaline phosphatase decreases during spermatozoal transport through epididymis.Acknowledgment. The work was supported by World Health Organization, Geneva (Project No. 76238).     

Biochemical changes in some acrosomal enzymes of spermatozoa during maturation

Goat spermatozoal hyaluronidase and acrosin show significantly increased activities during transition from caput to cauda epididymis. The activity of alkaline phosphatase decreases during spermatozoal transport through epididymis.     

The distribution of some enzymes involved in the steroidogenesis of hen's ovary

Riassunto È stata studiata con metodi istochimici la distribuzione della ⁵-3-idrossisteroide deidrogenasi ( ⁵-3-HSDH) e delle 17-idrossisteroide deidrogenasi (17-HSDH), DPN- e TPN-dipendenti, nell'ovario di gallina ovulante. Mentre la ⁵-3-HSDH è presente in tutti i tessuti a secrezione steroide dell'ovario, la 17-HSDH è localizzata solo nelle cellule della granulosa.     

Role of oxygen radicals scavenging enzymes in the protoporphyrin induced photohemolysis

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.     

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.     

Improved extraction and determination of some glycolytic enzymes in the human erythrocyte

Zusammenfassung Die Aktivitäten von 7 glykolytischen Enzymen wurden in normalen menschlichen Erythrozyten gemessen. Kurze Ultraschall-Hämolyse und modifizierte Test-Bedingungen führten, verglichen mit den höchsten Werten, zu signifikant höheren Aktivitäten.     

Ethanol metabolizing system inDrosophila melanogaster: subcellular distribution of some main enzymes

Summary The subcellular distribution of some enzymes which play a part in ethanol metabolism have been determined by differential centrifugation of homogenates of adultD. melanogaster flies of various genotypes. Aldehyde dehydrogenase, recently discovered inD. melanogaster, is present in the five genotypes studied. It has been found however to be, in vitro at least, most active in a strain lacking both alcohol dehydrogenase and aldehyde oxidase.     

Hydrogen peroxide protects tobacco from oxidative stress by inducing a set of antioxidant enzymes

Tolerance against oxidative stress generated by high light intensities or the catalase inhibitor aminotriazole (AT) was induced in intact tobacco plants by spraying them with hydrogen peroxide (H₂O₂). Stress tolerance was concomitant with an enhanced antioxidant status as reflected by higher activity and/or protein levels of catalase, ascorbate peroxidase, guaiacol peroxidases, and glutathione peroxidase, as well as an increased glutathione pool. The induced stress tolerance was dependent on the dose of H₂O₂ applied. Moderate doses of H₂O₂ enhanced the antioxidant status and induced stress tolerance, while higher concentrations caused oxidative stress and symptoms resembling a hypersensitive response. In stress-tolerant plants, induction of catalase was 1.5-fold, that of ascorbate peroxidase and glutathione peroxidase was 2-fold, and that of guaiacol peroxidases was approximately 3-fold. Stress resistance was monitored by measuring levels of malondialdehyde, an indicator of lipid peroxidation. The levels of malondialdehyde in all H₂O₂-treated plants exposed to subsequent high light or AT stress were similar to those of unstressed plants, whereas lipid peroxidation in H₂O₂-untreated plants stressed with either high light or AT was 1.5- or 2-fold higher, respectively. Although all stress factors caused increases in the levels of reduced glutathione, its levels were much higher in all H₂O₂-pretreated plants. Moreover, significant accumulation of oxidized glutathione was observed only in plants that were not pretreated with H₂O₂. Extending the AT stress period from 1 to 7 days resulted in death of tobacco plants that were not pretreated with H₂O₂, while all H₂O₂-pretreated plants remained little affected by the prolonged treatment. Thus, activation of the plant antioxidant system by H₂O₂ plays an important role in the induced tolerance against oxidative stress. Received 11 December 2001; received after revision 25 January 2002; accepted 4 February 2002