Ceruloplasmin Oxidase Activity Research Articles

The inhibition of bovine ceruloplasmin oxidase activity by thiomolybdates in vivo and in vitro: a reversible interaction

The administration of pharmacological doses (100 mg Mo) of trithiomolybdate or tretrathiomolydbate to ruminants causes a transient apparent decrease in the ceruloplasmin oxidase activity of plasma and a more persistent increase in copper bound to plasma albumin Sephadex gelfiltration and/or dilution of “inhibited” samples taken from an infused animal or of plasma treated with thiomolybdate in vitro restores activity back to pretreatment levels. The increase in albumin bound copper does not appear to be related to ceruloplasmin breakdown. It is concluded that, contrary to a recent report, the inhibition of ceruloplasmin oxidase activity is reversible and thus unlikely to be of pathological relevance, since circulatory thiomolybdate concentrations in molybdenotic animals are likely to be very low. It is recommended that thiomolybdate preparations used for in vitro and in vivo studies should be carefully purified by Sephadex chromatography.

Influence of copper supplementation on blood and liver copper in cattle fed tall fescue or quackgrass.

Copper concentrations were measured in naturally Cu-deficient and Cu-supplemented yearling Hereford heifers fed tall fescue (Festuca arundinacea Schreb.) or quackgrass (Agropyron repens [L] Beauv.) forage. The data were used to establish a relationship between dietary Cu supplementation and accumulation of liver Cu, and to test the influence of diet and Cu supplementation on blood plasma Cu and ceruloplasmin oxidase activity. Dietary Cu supplementation was positively correlated with accumulation of liver Cu; the rate of increase in liver Cu levels diminished at high supplementation rates (liver Cu = 410.43 - 353.47 x e-.00295 x mg Cu supplement; R2 = .740), suggesting an efficient mechanism preventing fast, toxic Cu-overloading in cattle. The linear relationship (R2 = .7878) between blood plasma Cu and ceruloplasmin oxidase activity indicated that similar percentages of blood plasma Cu were present as ceruloplasmin in deficient, normal and Cu-supplemented cattle. However, the portion of plasma Cu occurring as ceruloplasmin changes significantly with type of feed. When compared with quackgrass, tall fescue not only produced rapid Cu depletion in unsupplemented cattle, but affected intermediary Cy metabolism and activity of Cu-enzyme ceruloplasmin differently at all levels of experimental Cu supplementation.

Micro-dosage automatisé de la céruloplasmine plasmatique par mesure de l'activité oxydasique chez les bovins et les ovins

An automated method for the determination of plasma ceruloplasmin in bovine and ovine species is described. The analytic principle of Holmberg and Laurell (1951), based on protein oxidase activity, has been applied to a discrete computerized analyzer (Isamat, Isa Biologie, 94230 Cachan, France). Using this method a single operator can determine the oxidase activity of 500 plasma ceruloplasmin samples per day. The method is accurate (2.6% precision for mean values), linear over a range of 7-240 mcg/100 ml in copper equivalents and low in cost because small volumes of reagents can be used; it also correlates well with results from standard atomic absorption spectrophotometry and single radial immunodiffusion methods (correlation coefficients: 0.944 to 0.968). The conservation of oxidase activity is adequate and plasma ceruloplasmin oxidase activity determination can be used for assessing copper nutritional state and for screening inflammatory processes in bovine and ovine herds.

Coagulation Factor V contains copper ion.

Preparations of bovine and human coagulation Factor V were analyzed for copper using both atomic absorption and atomic emission spectroscopy. All preparations of the bovine and human protein were found to contain copper ion at a ratio of 1 copper ion bound per mol (Mr = 330,000) of Factor V. As a result of copper binding and sequence homology between ceruloplasmin and Factor V, bovine Factor V and thrombin-activated Factor V (Va) were assessed with respect to their visible and near ultraviolet absorption spectra and to their ability to oxidize N,N-dimethyl-p-phenylenediamine (a substrate for ceruloplasmin). Factor V and Factor Va exhibited absorption spectra with no maxima at either 310 or 610 nm, indicating that the copper is not bound in a site analogous to Type I or Type III copper sites in ceruloplasmin. Further, Factor V and Factor Va are not capable of serving as catalysts for the oxidation of N,N-dimethyl-p-phenylenediamine under solution conditions that are optimum for ceruloplasmin oxidase activity. These data suggest that the copper ion bound to Factor V may be functionally and structurally distinct from the Type I and Type III copper ion bound to ceruloplasmin.

99Mo metabolism in sheep after the intravenous injection of [ 99Mo] thiomolybdates

[ 99Mo]di-,tri-, and tetrathiomolybdate (5.4 to 62.5 mg of Mo) were given by intravenous injection to sheep maintained on a sulfur supplemented (3 g of S/kg) diet. All the compounds were metabolized very rapidly over the first 15 min postinjection, but relatively slowly thereafter, with a t 1 2 of about 30 hr for dithiomolybdate and 40 h for tri- and tetrathiomolybdate. The [ 99Mo] metabolites present in plasma were identified by Sephadex G-25 chromatography. The main fate of the compounds injected appeared to be stepwise transformation to molybdate and subsequent rapid urinary elimination. Over 90–100 hr more than 90% of the radioactivity was excreted in urine, compared to less than 5% in the feces. The trichloroacetic acid (TCA) solubility of plasma copper and the diamine oxidase activity of ceruloplasmin was depressed, particularly over the first 15 min postinjection and a more persistant TCA-insoluble Cu fraction was apparent.

Development of glutathione peroxidase activity during dietary and genetic copper deficiency

Copper deficiency was produced in developing rodents to study a possible interaction between copper and the selenoenzyme, glutathione peroxidase (GSH-Px). Dietary copper deficiency was investigated in Sprague-Dawley rats and in three mouse strains (C57BL, C3H/HeJ, C58); genetic copper deficiency was studied in two of the mouse strains, C57BL and C3H/HeJ, using brindled mice. In certain cases it appeared that copper deficiency was associated with depressed liver GSH-Px activity; values from copper-deficient livers were 40-70% of control values. However, the decrease in liver GSH-Px in both rats and mice was only observed when body weight was also depressed and did not necessarily correlate with copper deficiency signs, such as lower serum ceruloplasmin or liver cytochrome oxidase activities. In weanling rats, serum GSH-Px activity was normal despite a 60% reduction in liver activity. Mouse liver GSH-Px activity rose fourfold during the first 3 weeks of life to 75% of the adult level. Rat liver GSH-Px also increased during the suckling period. When perinatal copper deficiency, nutritional or genetic, was severe enough to retard growth, liver GSH-Px activity was depressed. Unlike rats, adult murine liver GSH-Px was equivalent in males and females.

Serum copper concentration and hepatic enzyme induction during long-term therapy with anticonvulsants.

We evaluated hepatic enzyme induction by measuring urinary D-glucaric acid and serum gamma-glutamyltransferase in a group of 40 adult epileptics of both sexes who were receiving long-term treatment with phenobarbital and (or) phenytoin. Total concentrations of copper and ceruloplasmin in their serum and the oxidase activity of ceruloplasmin were significantly greater than in the control group. However, non-ceruloplasmin copper and specific oxidase activity of the ceruloplasmin (activity per gram) were unchanged. A highly significant relationship was found between gamma-glutamyltransferase and (a) copper (r = 0.682, p less than 0.001), (b) ceruloplasmin (r = 0.523, p congruent to 0.001), and (c) the oxidase activity of the ceruloplasmin (r = 0.598, p less than 0.001). There is also a significant correlation of hemopexin with ceruloplasmin (r = 0.531, p congruent to 0.001) and the oxidase activity of the ceruloplasmin (r = 0.598, p less than 0.001). These results suggest that hypercupremia in patients undergoing long-term anticonvulsant therapy is a direct result of hepatic enzyme induction caused by the drugs that induce synthesis of ceruloplasmin.

The protective action of ceruloplasmin on copper ion stimulated lysis of rat erythrocytes

1. 1. Human ceruloplasmin effectively protects washed rat erythrocytes against copper ion stimulated lysis. 2. 2. Experiments suggest that the protective action is not associated with (a) the oxidase activity of ceruloplasmin, (b) the protein's Superoxide radical scavenging ability, (c) its ability to weakly bind cupric ions (nonspecific binding) or (d) ceruloplasmin bound sialic acid.

Inhibitory effects of sulfhydryl compounds on the ceruloplasmin oxidase activity and the carrageenin-induced inflammation in rats

Inhibitory effects of sulfhydryl compounds on the ceruloplasmin oxidase activity and the carrageenin-induced inflammation in rats

Electrophoretic analysis of the plasma and urinary proteins and the ceruloplasmin oxidase activity of heterozygous tortoiseshell (mo to/+) female mice ( Mus musculus)

1. 1. The plasma and urinary proteins of two strains of normal (+/+) and heterozygous tortoiseshell (Mo to/+) female mice were separated by polyacrylamide gel electrophoresis (PAGE). 2. 2. The plasma ceruloplasmin oxidase activity of +/+ and Mo to/+ female mice was determined by light spectrophotometry. 3. 3. The plasma proteins (e.g. transferrin, albumins, ceruloplasmin) and major urinary proteins (MUPs) of +/+ and Mo to/+ female mice of both strains investigated exhibited identical electrophoretic patterns. 4. 4. The plasma ceruloplasmin oxidase activity of +/+ female mice was consistently higher than that of Mo to/+ female mice.

Failure to confirm abnormal copper utilization in crinkler (cr) mice

A number of aspects of copper utilization have been studied in crinkled mice, the symptoms of which have been claimed to result from copper deficiency. In none of these aspects has any evidence been found to support this contention.1. Copper concentrations in liver, kidney, and brain, and serum ceruloplasmin oxidase activity were normal incr/cr mice.2. Copper concentrations in cultured lung fibroblasts and kidney epithelial cells derived fromcr/cr mice were normal.3. The elution profile of bound copper by gel-filtration chromatography of liver homogenates was the same in +/? andcr/cr mice.4. Neither maternal nor direct copper supplementation resulted in any reduction in mortality ofcr/cr mice.5. No increase in the concentration of hair sulfhydryl groups was apparent incr/cr mice.6. Histological studies revealed that the thin skin incr/cr mice owed to a reduction of the cutis; the epidermal and dermal layers were of normal thickness.7. Lysyl oxidase activity was normal in extracts of skin from 6-day-oldcr/cr mice, and in the culture medium ofcr/cr lung fibroblasts.8. Chemical analysis of brain myelin from 21- and 60-day-oldcr/cr mice showed no differences from +/? mice.

Total serum copper and ceruloplasmin levels following administration of copper aspirinate to rats and guinea-pigs.

Total serum copper and ceruloplasmin oxidase activities have been measured over a 24-h period in rats and guinea-pigs treated with 100 mg/kg body weight of copper (II) aspirinate. In the rat, administration s.c. produced higher total serum copper levels than oral administration at all time intervals studied, whereas in the guinea-pig, oral administration produced the higher level after 1 h and s.c. administration the higher level after 5 h. In both species, the rate of elimination of the additional copper was faster following oral administration. Ceruloplasmin oxidase activity appeared to be inhibited in certain cases but rose in all cases except for orally treated rats after 24 h. The initial rise in serum copper was due mainly to copper present on albumin. The increased albumin copper was detected directly by electrophoresis of serum samples and subsequent determination of the copper level in the portions of the strip which contained proteins. After s.c. administration to the rat, the amount of ultrafilterable copper was raised by a detectable amount. 7 h after s.c. or oral administration of copper aspirinate, the thiol concentration of the serum was reduced in both rats and guinea-pigs. The relationship of these levels to the anti-inflammatory action of copper (II) aspirinate in rats and guinea-pigs is discussed.

Copper and ceruloplasmin activity in human amniotic fluid

The variation in the level of copper and ceruloplasmin oxidase activity in human amniotic fluid from 20 weeks' gestation to term was reported. The protein content of amniotic fluid decreased toward term. A definite decreasing trend of concentration of copper, expressed both as nanograms of copper per milliliter of amniotic fluid and nanograms of copper per milligram of protein, was also observed from midgestation toward term. Ceruloplasmin, on the other hand, demonstrated a significant increase from the period 20 to 38 weeks' gestation, with a subsequent decline after 38 weeks.

Amine oxidase activity of ceruloplasmin and copper (II) complexes with derivatives of anthranilic acid

Amine oxidase activity of ceruloplasmin and copper (II) complexes with derivatives of anthranilic acid

Laboratory and histological similarities between Wilson's disease and rats with copper toxicity.

Rats were injected intraperitoneally with copper-lactate daily for over 160 days (total dose of 30 mg copper in each animal). At 120 to 160 days of copper administration, animals developed symptoms similar to those of Wilson's disease, i.e., kidney functional disturbances, proteinuria, aminoaciduria, decreased blood ceruloplasmin oxidase activity and increased urinary copper excretion. Cirrhosis was found in some animals. Tubular necrosis of the kidneys, liver fibrosis and tigrolysis of thalamic nerve cells were also found. Copper depositions were observed in liver parenchymal cells, renal tubular epithels, thalamus glia cells and on the Descemet's membrane of the cornea. The similarities between induced copper- intoxication in rats and Wilson's disease are discussed.

The role of ceruloplasmin in Fe(III)—transferrin formation in vitro

The demonstration of iron mobilization by ceruloplasmin (EC 1.12.3.1) in perfused dog liver [l] and studies on copper-deficient animals [2] strongly suggest that ceruloplasmin is a direct molecular link between copper and iron metabolism. The ferroxidase activity of ceruloplasmin was first observed in [3] with the confirmation [4] that the oxidase activity of ceruloplasmin was greater for iron than for any other substrate. Thus, it was suggested that the ceruloplasmin catalyzed oxidation of iron and was an essential step on the pathway of Fe(III)-transferrin formation. However, several observations may be cited against this theory: (i) There is no evidence for defective iron mobilization in patients with Wilson’s disease [5]; (ii) Rat ceruloplasmin exhibits a relatively low ferroxidase activity when compared to the corresponding human or pig proteins [6]; (iii) The ferroxidase activity of human and rat ceruloplasmin at physiological pH is only -1/7th of the activity, that it has at pH 6.7 and 6.0, respectively [71. According to [8] transferrin binds ferrous iron at the specific metal binding sites and the resulting Fe*‘-transferrin complex is highly susceptible to oxidation. In plasma, transferrin also reacts very poorly with iron which has been oxidized to Fe3’ by an agent such as ceruloplasmin [8]. Here, we have attempted to clarify the role of ceruloplasmin in transferrin formation in vitro, using ferrous iron and ferritin as sources of iron.

Effect of Tall Fescue and Quackgrass on Copper Metabolism and Weight Gains of Beef Cattle

Rapid copper depletion without clinical signs of copper deficiency was found in yearling beef heifers under natural Klamath Basin (Oregon) conditions. Copper metabolism in the animals was influenced by grass species grown as feed in the muck soils of this area. Consumption of tall fescue, Festuca arundinacea Schreb., reduced liver copper stores (P < .02) and decreased plasma copper (P < .001) and ceruloplasmin oxidase activity (P < .001) to a deficiency level in less than 4 months. At the same time cattle fed quackgrass, Agropyron repens (L.) Beauv., maintained normal blood copper and ceruloplasmin activity levels and increased liver copper stores. Quackgrass was lower than fescue in copper content (4.6 ppm and 6.6 ppm, respectively), molybdenum (1.2 ppm and 2.3 ppm, respectively), sulfur (.16% and .34%, respectively) and manganese (38 ppm and 91 ppm, respectively). Tall fescue produced lower (P < .001) daily weight gains (.55 kg) than quackgrass (.71 kg). Daily gains were not improved by copper supplementation. Grass species and/or copper supplementation did not affect whole blood zinc and liver iron, molybdenum and zinc concentrations.

Ceruloplasmin Elevation and Synthesis in Rats with Transplantable Tumors

In rats with transplantable mammary or hepatic tumors, plasma ceruloplasmin oxidase activity was increased 50--200%. This occurred progressively with tumors weighing 0.3% of body weight of more, and did not occur upon sham operation or implantation of normal tissue. Incorporation of [3H]-leucine indicated a specific enhancement of ceruloplasmin synthesis in the tumor-bearing rats, and a greater state of activation of the enzyme was also observed. The mechanism of the increase in ceruloplasmin levels in rats and humans with cancer thus appears to involve increased synthesis and activation of the enzyme.

Blood-reduced glutathione, pyruvic acid, citric acid, ceruloplasmin oxidase activity and certain mineral changes in diabetes mellitus before and after treatment.

In maturity onset diabetes the blood levels of total blood keto acids in terms of pyruvic, serum citric, calcium are significantly higher than in normal adults, while there is a decrease in reduced-blood glutathione, serum zinc, potassium and sodium levels. There were no significant differences between diabetes and normal adults in the serum levels of copper, ceruloplasmin oxidase activity, iron and magnesium.

Blood-reduced glutathione, serum ceruloplasmin and mineral changes in juvenile diabetes.

In cases of juvenile diabetes, there were lower than normal levels of reduced glutathione, ceruloplasmin oxidase activity, zinc, copper and sodium, while the other elements show no significant changes. The lower level of serum zinc, copper and sodium may be due to the osmotic diuresis and consequent polyurea of diabetes.