ABSTRACT
Superoxide dismutases (SOD), which are enzymes scavenging the superoxide radical, were studied in two variant lines of the B16 melanoma: B16F1 with low metastatic potential and B16F10 with high metastatic potential. SOD activity was measured by a method utilizing reduction in the chemiluminescence of luminol. Using cell free extracts it was shown that the highly metastatic B16F10 cell line has a SOD activity lower (20.70 +/- 3.07) units/mg protein, n = 8, than that of the less metastatic B16F1 cell line (81.38 +/- 6.78) units/mg protein, n = 8. Acrylamide gel electrophoresis suggested that Mn-SOD activity is higher in B16F1 cells.
Subject(s)
Melanoma, Experimental/enzymology , Superoxide Dismutase/metabolism , Animals , In Vitro Techniques , Mice , Neoplasm MetastasisABSTRACT
1,2-Dimethylhydrazine-induced large bowel tumors in adult male rats contained significantly lower levels of xanthine oxidase and xanthine dehydrogenase activities when compared to levels in normal intestinal tissue. Xanthine dehydrogenase activity in the blood serum of DMH-treated rats was significantly higher than that of the control animals.
Subject(s)
Colonic Neoplasms/chemically induced , Xanthine Oxidase/metabolism , Animals , Colonic Neoplasms/enzymology , Dimethylhydrazines , Male , Rats , Xanthine Dehydrogenase/blood , Xanthine Dehydrogenase/metabolismABSTRACT
Hepatic lesions by D-L-ethionine in rats produce a significant increase in the blood serum xanthine dehydrogenase activity. Cupric acetate is a potent inhibitor (Ki = 3.42 X 10(-6) M) of the xanthine dehydrogenase activity. Ethionine protects against the inhibitory effect of cupric acetate by formation of a copper complex with behaviour different from that of free ethionine.
Subject(s)
Copper/pharmacology , Ethionine/pharmacology , Ketone Oxidoreductases/antagonists & inhibitors , Organometallic Compounds , Xanthine Dehydrogenase/antagonists & inhibitors , Animals , Female , Liver/drug effects , Rats , Xanthine Dehydrogenase/bloodABSTRACT
Cold acclimatization (2-5-C) not less than 20 days increases the blood serum xanthine dehydrogenase in normal as in CCl4 poisoned rats. The enzyme of the liver remains unchanged
Subject(s)
Rats , Animals , Male , Carbon Tetrachloride Poisoning/blood , Xanthine Dehydrogenase/bloodSubject(s)
Ketone Oxidoreductases/antagonists & inhibitors , Liver/enzymology , Neoplasms/urine , Pterins/urine , Xanthine Dehydrogenase/antagonists & inhibitors , Animals , Carcinoma, Ehrlich Tumor/physiopathology , Cells, Cultured , Female , Male , Mice , Neoplasms, Experimental/physiopathology , Pterins/pharmacology , Rats , Xanthine Dehydrogenase/isolation & purificationABSTRACT
Liver X.O. activity does not change significantly in tumor bearers although it is known that in this case there is a severe protein deficiency (hypoproteinosis). A decrease in the blood serum X.D. activity was observed in tumor bearing rats but no change occurred in the level of the plasmatic protein. It was suggested that the fall in the blood serum enzyme can be due to factors not correlated with the protein deficiency due to the animals inanition.
Subject(s)
Liver/enzymology , Neoplasms, Experimental/enzymology , Xanthine Oxidase/metabolism , Animals , Blood Proteins/deficiency , Fasting , Liver/metabolism , Mice , Mice, Inbred Strains , Protein Deficiency/etiology , Rabbits , Rats , Rats, Inbred Strains , Xanthine Oxidase/bloodABSTRACT
Alloxan is an inhibitor of the enzyme xanthine: NAD+ oxido reductase (E.C.1.2.1.37). Alloxan acts as an electron acceptor and competes "in vitro" with the tetrazolium salt used as electron acceptor in the assay system used for the determination of the dehydrogenase activity of the enzyme. The alloxan inhibition was reverted when phenazine methosulfate (PMS) was added to the system.
Subject(s)
Alloxan/pharmacology , Ketone Oxidoreductases/antagonists & inhibitors , Tetrazolium Salts/pharmacology , Xanthine Dehydrogenase/antagonists & inhibitors , Electron Transport , In Vitro Techniques , Kinetics , NAD/pharmacology , Phenazines/pharmacology , Xanthine Dehydrogenase/blood , Xanthine Dehydrogenase/pharmacologyABSTRACT
The steady-state concentrations of glutamine, glutamate and ammonia in the kidney cells might regulate the rate of renal xanthine dehydrogenase activity. Both glutamate and glutamine were found to be effective inhibitors of the renal xanthine dehydrogenase activity in vivo. The inhibition by glutamate depends essentially on the glutaminase inhibition.
Subject(s)
Glutaminase/metabolism , Ketone Oxidoreductases/metabolism , Kidney/enzymology , Xanthine Dehydrogenase/metabolism , Animals , Cytosol/enzymology , Glutamates/pharmacology , Glutamine/pharmacology , Kinetics , Male , RatsABSTRACT
Xanthine dehydrogenase activity was determined in blood serum of rats in which diabetes had been induced by alloxan administration. The results show that there is no statistical significance in the difference found for normal and diabetic rats. Alloxan produced an inhibition in the enzyme activity in animals in which a carbon tetrachloride hepatotoxicity had been induced.
Subject(s)
Carbon Tetrachloride Poisoning/enzymology , Diabetes Mellitus, Experimental/enzymology , Ketone Oxidoreductases/blood , Liver/pathology , Xanthine Dehydrogenase/blood , Alloxan/pharmacology , Animals , Carbon Tetrachloride Poisoning/complications , Diabetes Mellitus, Experimental/complications , Kinetics , Male , RatsABSTRACT
In this study it was shown that the rat blood serum xanthine oxidase (X.O.) is differently inhibited by -SH reagents and seems that the blood serum enzyme has two types of -SH groups, one reacting relatively rapidly and unrelated to the enzyme activity and the other reacting slowly to produce inactivation. The results presented suggest that there are only few fundamental relationship between the different -SH reagents used and the inhibition of the enzyme activity in the blood serum. With mercurials it was shown that the most reactive -SH groups of the rat blood serum are not related to the X.O. activity, but when sufficient number are reacted the enzyme is structurally altered so that inhibition appears. With oxidants such as iodine the inhibition of the X.O. activity of rat blood serum seems to be not related specifically with the oxidation of -SH groups.
