Liver Xanthine Oxidase Activity Research Articles

Measurement of xanthine oxidase activity in some human tissues. An optimized method.

Xanthine oxidase activity in human liver or jejunum homogenates was measured by using 8-14C-hypoxanthine (HX) as a substrate. Products of oxidation were separated by thin-layer chromatography on MN Polygram cellulose and located by autoradiography. The percentage of oxidation was measured by liquid scintillation. Main parameters of the enzyme reaction have been optimized. Repeatability and reproducibility of the overall procedure give a variation coefficient of 6.3 and 7.7%, respectively. Minimal detectable enzymatic activity corresponds to an oxidation percentage of 1% (HX) for liver and jejunum. The reliability and practicability of this method allow a rapid diagnosis of xanthine oxidase deficiency. Normal values obtained by this optimized method range between 25 and 42 mukat . kg-1 protein for liver and 18 and 40 mukat . kg-1 protein for jejunum.

Bovine Milk Xanthine Oxidase, Blood Lipids and Coronary Plaques in Rabbits

The effects of prolonged intravenous administration of bovine milk xanthine oxidase (EC 1.2.3.2.) on blood lipids and arterial integrity were measured to determine if the administration of this enzyme produces metabolic changes conducive to plaque formation. New Zealand White rabbits were injected intravenously with bovine milk xanthine oxidase at 4-day intervals during a 13-week test period. At the end of the test period, the rabbits were killed and blood, heart, aorta, liver, and kidneys were collected and evaluated. Rabbits injected with phosphate buffer or acid-denatured xanthine oxidase for the same length of time served as negative controls. Additional rabbits fed a diet containing 3% added cholesterol for the same time period served as positive controls. The administration of xanthine oxidase in large amounts over a prolonged period did not alter serum cholesterol or triglyceride levels and did not reduce plasmalogen levels in the aorta or heart. Xanthine oxidase administration did not induce arterial plaque formation. Cholesterol feeding over the same time period increased serum cholesterol levels, reduced liver xanthine oxidase activity levels and resulted in a marked development of arterial plaques. Althouth xanthine oxidase activity was found in liver from all rabbits, enzyme activity was not detectable in aorta, heart or kidneys from any rabbit. Free or complexed bovine milk xanthine oxidase could not be demonstrated in heart, aorta, liver or kidneys from any of the rabbits with immunodiffusion or with immunofluorescent techniques. The study showed that when large intravenous doses of bovine milk xanthine oxidase were given to rabbits, the enzyme was not deposited in heart, aorta, liver or kidneys. The study also showed that large intravenous doses of xanthine oxidase over prolonged periods did not deplete arterial or coronary tissue plasmalogens, and did not induce arterial plaque formation.

Developmental changes in rat liver xanthine oxidase(s) and its intracellular distribution.

Developmental change and subcellular distribution of xanthine oxidase in the rat liver were examined. The specific activity of the fetal liver xanthine oxidase increased sharply to the levels of the adult liver on the day of the birth. After birth, the activity dropped rapidly and on the 14th day after birth it was about 1/4 of adult level. Then the activity was regained and around 28th day after birth it was about the same as in adult level. In the livers from 80 days old rats, about 60% of total xanthine oxidase activity was found in soluble fraction and the rest was distributed among particulate fractions including microsomal, lysosomal, mitochondrial and nuclear fractions. In contrast to the adult livers 80%. of total xanthine oxidase activity in fetal liver was found to be in particulate fractions. From kinetic studies of xanthine oxidases in particulate and soluble fractions it was suggested that xanthine oxidase in soluble fraction and xanthine oxidase in particulate fraction might be different in their natures of protein molecule.

Growth inhibitory action of saccharin and cyclamate on rats receiving a poor rice diet.

1. The effect of saccharin and cyclamate on growth of young rats fed on a poor rice diet or a balanced diet was investigated.2. Saccharin and cyclamate retarded the growth of rats on the multi-deficient diet but not of those on the well-balanced diet during an 8-week feeding period.3. The sweeteners did not produce any macroscopic or microscopic changes in the liver, kidneys, intestines, spleen or lungs of the animals receiving the poor rice diet other than the changes resulting from the nutritional deficiency of the diet.4. The sweeteners did not inhibit the liver xanthine oxidase activity of rats receiving the poor rice diet to an extent greater than the inhibition brought about by the deficiency of protein in the diet.5. When given by intubation to healthy rats, the sweeteners inhibited the induction of liver tryptophan oxygenase; given in vitro, they inhibited the succinate dehydrogenase activity of rat liver mitochondria.

Influence of Zinc and Vitamin D on Plasma Amino Acids and Liver Xanthine Oxidase in Rats

Plasma amino acids and liver xanthine oxidase activity were determined in rats fed a control diet with and without calciferol or fed diets providing 9% casein with and without added zinc and calciferol. Reduction of dietary protein resulted in a significant decrease in xanthine oxidase activity, concentrations of plasma threonine, methionine, isoleucine, leucine and phenylalanine, and in elevated histidine levels. Addition of calciferol to diets containing added zinc decreased the levels of plasma isoleucine, leucine, threonine and lysine. Lysine in plasma was also decreased by calciferol supplementation of the low protein diet and by the addition of zinc to this diet. Xanthine oxidase activity was lowest in animals fed the low protein diet without calciferol and zinc. The apparent interaction between zinc and vitamin D closely approached significance at the 5% level. The results indicated that xanthine oxidase activity in animals fed low protein decreased with increased plasma lysine, which was observed in animals maintained without dietary sources of zinc and calciferol.

Activité xanthine-oxydasique rénale, hépatique et san-guine chez le rat au cours de l'intoxication expérimentale au nitrate d'uranyle

In uranyl nitrate-induced tubulonephritis in the rat with toxic hepatitis, the following observations were made: significant decrease, during 24 hours, of the renal xanthine oxidase activity followed by a very marked rise at the 96th hour after the beginning of the intoxication; more clear-cut fall of the liver xanthine oxidase activity as soon as the 24th hour, followed by slight reactivation and by continuous decrease until the 96th hour; rise in the plasma xanthine oxidase activity, with its maximum at the 48th hour. The contents in proteins, DNA and RNA as well as the hematocrits were studied.

Liver Xanthine Oxidase Activity of Mice Infected with Schistosoma mansoni

Liver Xanthine Oxidase Activity of Mice Infected with Schistosoma mansoni

Effect of dietary history on liver xanthine oxidase activity of adult and growing rats.

Effect of dietary history on liver xanthine oxidase activity of adult and growing rats.

Effect of Source and Level of Dietary Protein on Liver Enzyme Systems in the Young Pig

Forty-eight young, rapidly growing, crossbred pigs were fed 8, 12, 16 or 20% protein starch-base diets, with the protein supplied by fish filet flour (FF), dried skim milk (DS) or soybean meal (SM), in an attempt to determine whether the activities of selected liver enzyme systems would reflect level and quality of dietary protein. The liver homogenates (1:5:liver:ice water) were assayed to determine the activities of xanthine oxidase (µliters O2/hour/g wet liver), glutamic-pyruvic transaminase (mg pyruvic acid formed/30 minutes/g wet liver) and succinic dehydrogenase (mg formazan formed/30 minutes/g wet liver). Rate of gain and feed conversion efficiency were improved significantly as level of dietary protein was increased from 8 to 16%; liver weight and percentage nitrogen also increased significantly with increasing level of dietary protein. Liver xanthine oxidase activity was variable and did not generally reflect source or level of dietary protein. The activity of glutamic-pyruvic transaminase increased linearly with increasing levels of dietary protein from DS and SM. Succinic dehydrogenase activity increased linearly with increasing levels of dietary protein for all sources of protein. Liver succinic dehydrogenase activity was more closely related to average daily gain, liver weight and per cent liver nitrogen than was either xanthine oxidase or glutamic-pyruvic transaminase activity. Further, more elaborate studies are necessary to determine the usefulness of liver enzyme activities in evaluating protein quality for the young pig.

Studies on the Growth, Physical Strength and Nutrition of Blind School-children (Part 7)

An experiment using weanling rats was proceeded to estimate the nutritional value of the boarding house diet of a blind school. The boarding house diet, experimental diet II, was obtained a plate for 22 consecutive days. Enriched feed, experimental diet III, was made by adding 40g skim milk per day per person to the diet II and by subtracting the equivalent weight of cereals from the diet II. Designating the experimental diet I, the farm village diet of the Tohoku District of Japan was used as a contrasting poor diet. Experimental diet I, II and III contained 8%, 14% and 16.4% protein, 2.1%, 33% and 46.6% animal protein to total protein, 27mg%, 106.4mg% and 207.9mg% calcium respectively.Twenty-four weanling rats of Wister strain were divided into three groups I, II and III each consisting of four males and four females, and each group was fed with the respective experimental diet I, II and III. During and after 46 days feeding, the animals were examined on the following items as the indication of the nutritional values of these diets: increasing rate of body weight, efficiency ratio of diet, protein efficiency ratio, weights of liver, spleen. and kidney, body length, lengths and weights of femur and tibia, content of minerals in the bones, serum protein concentration, alkaline phosphatase activity and liver xanthine oxidase activity. The followings were concluded from the experiment.The diet III had the highest and the diet I had the lowest nutritional values for the development of rats, and the differences were statistically significant, especially in the items of body weight, efficiency ratio of diet, body length, content of minerals in bones and liver xanthine oxidase activity. In the items of serum protein concentration, visceral weight and ratio of bone weight to body weight, there was no significant differences among each group of the three diets. However, the bone length to body length and serum alkaline phosphatase activity were highest in the group I and lowest in the group III, showing the statistically significant differences.

Metabolic activity of inosine on the incorporation of D-riboflavin into rat-liver xanthine oxidase system.

1. Metabolic activity of inosine on the incorporation of riboflavin into rat-liver xanthine oxidase system was studied.2. The effect of ingested inosine on liver nitrogen was scarcely recognized.3. The tendency of the increase in total riboflavin and flavin mononucleotide in the liver of the rats receiving inosine was observed, but the change in the contents of free riboflavin and flavin-adenine dinucleotide was not observed.4. The tendency of the increase in the activity of liver xanthine oxidase in the rats receiving inosine was observed.

The Bursa of Fabricius and Xanthine Oxidase Activity of Liver and Kidney Following Dietary Supplementation of Iodinated Casein to Chickens

Abstract The role of the bursa of Fabricius (bursa), a gland peculiar to young aves, is not yet well established. Recent reports demonstrated the importance of the bursa in antibodies production, Glick (1960) and Perek and Drill (1962), control of enzymic reaction, Bedrak (1962) and its inhibitory effect upon release of adrenal ascorbic acid (AAA), following stress treatment. Bursectomized birds react to stress inducements similarly to rats and other mammals by depletion of their AAA and adrenal cholesterol, Perek and Eilat (1960) and Perek and Bedrak (1962). Nutritional stress in mammals such as protein deficiency elicitates a marked decrease in liver xanthine oxidase (XO) activity (Litwack et al., 1950; Wainio et al., 1953; and Shirley et al., 1959). Supplementation of iodinated casein (protamone) at 500 p.p.m. level to the diet of laying hens imposes a nutritional stress, affecting body weight and egg production (Perek and Bedrak; unpublished data). Thus, the present…

Reduction of Liver Xanthine Oxidase Activity and Iron Storage Proteins in Rats Fed Excess Zinc

Reduction of Liver Xanthine Oxidase Activity and Iron Storage Proteins in Rats Fed Excess Zinc

Relationsnip Between the Nutritive Value of Dietary Protein and Liver Xanthine Oxidase Activity in Young Rats

Relationsnip Between the Nutritive Value of Dietary Protein and Liver Xanthine Oxidase Activity in Young Rats

Relationsnip Between the Nutritive Value of Dietary Protein and Liver Xanthine Oxidase Activity in Young Rats

The relationship between the nutritive value of dietary protein and the activity of lievr xanthine oxidase in growing rats as related to the growth rate and the protein efficiency ratio has been investigated.The response curve of liver xanthine oxidase plotted against the protein level in the diet was essentially exponential, and the lower portion of this curve was linear. The slope of this straight portion, i.e., the tangent of the curve was observed to reflect the quality of dietary protein from comparison with the growth rate and the protein efficiency ratio.

Xanthine oxidas activity and iron storage in the liver.

SummarySodium tungstate was added to the diet to decrease liver xanthine oxidase activity. There were no concomitant changes in liver iron or iron absorption associated with the decrease in xanthine oxidase activity.

Nitrogen Balance and Some Liver Enzymes in Adult Rats

Nitrogen balance is shown by the sum of the retentions and losses involving in all the tissue protein. It is questionable, however, whether or on the values obtained by this method show a true requirement of nitrogen needed for the good health of adult animals.We have studied the relationships between nitrogen balance and the liver nitrogen, and liver xanthine oxidase and succinic dehydrogenase in rats fed on diets containing various levels of casein. We have found that body weight and the liver nitrogen content slightly decreased, and liver xanthine oxidase and succinic dehydrogenase activities decreased considrably at the point of nitrogen equilibrium.

Studies on Amino Acid Supplementation and Protein Metabolism (II)

The supplementary effects of tryptophan, methionine, lysine and threonine to Japanese diet were examined by growth and activity of liver xanthine oxidase of rats as index of improvement of protein quality.The activity of liver xanthine oxidase was strikingly increased by supplementation of tryptophan and methionine, lysine and threonine, or four amino acids, but the growth response was not affected in each case, and there was no difference in these results between three groups.

Studies on Amino Acid Supplementation and Protein Metabolism (I)

The effects of supplementation of amino acids on rat liver xanthine oxidase activity were investigated, and the results obtained are as follow.1. Pyrophosphate buffer, pH 8.6 for the manometric assay of liver xanthie oxidase activity recommended by Dhungat et al. inhibited the endogenous respiration of rat liver homogenate.2. Adult rats were fed 9% casein diet added with 1% DL-methionine, DL-threonine, L-lysine, or L-phenylalanine, and the activity of liver xanthine oxidase were compared. The activity increased by the addition of methionine or threonine, but decreased by the addition of lysine or phenylalanine.3. The supplementary effects of methionine, tryptophan, lysine and threonine to polished rice on liver xanthine oxidase in adult rats were examined, and the supplementation with lysine and threonine to the rice diet promoted the growth of rats more than that of the supplementation with methionine and tryptophan, but the liver xanthine oxidase activity of the former was significantly lower than that of the latter.4. The effect of adding various amounts of DL-methionine to 18% amino acid powder diet on liver xanthine oxidase in young rats was examined, and the most highest liver xanthine oxidase activity was obtained at the 0.57% methionine level diet.5. An increase in xanthine oxidase activity occured when liver slices from protain-depleted rat was incubated in Ringer solution containg FAD, casein enzymatic hydrolyzated and methionine.

Nitrogen Balance and Some Liver Enzymes in Adult Rats

Nitrogen balance is shown by the sum of the retentions and losses involving in all the tissue protein. It is questionable, however, whether or on the values obtained by this method show a true requirement of nitrogen needed for the good health of adult animals. We have studied the relationships between nitrogen balance and the liver nitrogen, and liver xanthine oxidase and succinic dehydrogenase in rats fed on diets containing various levels of casein. We have found that body weight and the liver nitrogen content slightly decreased, and liver xanthine oxidase and succinic dehydrogenase activities decreased considrably at the point of nitrogen equilibrium.