Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.16.3.1 (ceruloplasmin)
 5,074 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Estrogen effects on plasma iron and ferroxidase activity in some mammals and domestic fowl are studied, to investigate a possible estrogen mechanism on iron through its action on the ferroxidase system. Although estrogen generally induces ceruloplasmin, iron mobilization, characterized by a rise in plasma iron, was evident only in rats and chickens. Gonadotrophin treatment confirmed these results. A decreasing affect on plasma iron was noted in rabbits and guinea-pigs, substantiated by some bibliographical data. Ferroxidase activity increased and a copper-dependent factor was evident in copper injected species. Iron mobilization, however, was produced only in rats and chickens. D-penicillamine treatment considerably lowered ferroxidase activity in rats and suppressed the estradiol increasing plasma iron effect. This response to the copper-chelating drug did not take place in the other species. This phenomenon could be explained by the presence of two copper-dependent ferroxidases (ferroxidase I or ceruloplasmin and ferroxidase II) in rat plasma, as recently published.
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PMID:The serum ferroxidase system and the effect of estrogen on plasma iron. 93 20

The activities of 2Cu,2Zn-superoxide dismutase, ferroxidase (ceruloplasmin), catalase and glutathione peroxidase were measured in the blood of rats during copper depletion. Two control groups of animals were used; one received the regular diet containing all essential components including copper and the other group was maintained on a diet, containing 1% the amount of copper in normal diet, copper being supplied as Cu(Leu)2 in the drinking water. Both groups showed no detectable differences, either in the copper content of blood or in the measured four enzymic activities. Excessive copper (injected intraperitoneally) caused only an insignificant rise in the enzymic activities (0-10%) compared to either control. After starting copper depletion ferroxidase activity decreases to 15% on the 15th day, while the 2Cu,2Zn-superoxide dismutase activity decreases to 40% on the 45th day. Ferroxidase activity shows rapid but transient changes immediately after perturbation in plasma copper levels. By contrast, the 2Cu,2Zn-superoxide dismutase activity more closely parallels the overall copper deficiency. Dietary repletion with copper raises the 2Cu,2Zn-superoxide dismutase activity to 94% and the ferroxidase activity to 80% of the control values within 36 h. Apart from the copper-dependent anemia catalase activity was decreased. However, 15 days after the start of the copper depletion catalase activity rises again and reaches the control value on the 40th day and a 30% stimulation was even seen on the 58th day. Upon copper repletion catalase activity reaches 166% of the control within 14 days. No copper-dependent differences of glutathione peroxidase activity were seen regardless whatever copper level was present in the rats.
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PMID:Copper deficiency and erythrocuprein (2Cu, 2Zn-superoxide dismutase). 97 14

Ferroxidase activity was increased in the aqueous humor from inflamed eyes compared to their uninflamed contralateral controls 24 h after intravitreal injection of 10 ng of endotoxin. Changes in ferroxidase activity and copper concentration paralleled each other indicating that the plasma copper transport protein ceruloplasmin (plasma ferroxidase) entered the inflamed aqueous humor from plasma through disrupted blood ocular barriers. The presence of ferroxidase activity would facilitate the removal of potentially damaging, free radical generating Fe+2. Therefore, plasma proteins may perform important protective functions in the inflamed intraocular fluids.
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PMID:Ferroxidase activity increases in the aqueous humor during the ocular inflammatory response. 267 23

Ferroxidase activity in human H-chain ferritin has been studied with the aid of site-directed mutagenesis. A site discovered by X-ray crystallography has now been identified as the ferroxidase centre. This centre is present only in H-chains and is located within the four-helix bundle of the chain fold.
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PMID:Identification of the ferroxidase centre in ferritin. 277 83

The oxidase activity of caeruloplasmin towards Fe II (ferroxidase) appears to be of physiological significance both in iron metabolism and as a serum anti-oxidant. We have developed an automated assay for ferroxidase using a centrifugal analyser. The method is quick and precise, and is not subject to interference by haemolysis, jaundice or lipaemia. Ferroxidase activities correlate significantly with caeruloplasmin and copper concentrations. Normal reference ranges have been measured.
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PMID:An automated method for the kinetic measurement of ferroxidase activity. 340 Sep 81

Ferroxidase II (Fox II) was developed in serum by acid incubation for 24 h. The resulting activity showed a strong positive correlation with the serum cholesterol concentration in normal subjects and patients with hyperlipidaemia. The potentiating effect of cholesterol on developed Fox II has been confirmed by the in-vitro addition of cholesterol to serum. There was no significant correlation between developed Fox II and caeruloplasmin (ferroxidase I) or between cholesterol and caeruloplasmin.
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PMID:Ferroxidase II activity and serum cholesterol. 350 45

Serum ferroxidase I (ceruloplasmin) and ferroxidase II activities were studied in 49 uremic patients under conservative treatment, in 79 patients undergoing hemodialysis and in 56 healthy subjects, as controls. Ferroxidase I was significantly higher in both groups of patients. Ferroxidase II was significantly elevated only in patients undergoing chronic hemodialysis. The cause of this difference is not clear, but seems to be of considerable interest.
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PMID:Serum ferroxidase I and II in uremic patients under conservative treatment and maintenance hemodialysis. 361 Mar 72

Apoferritin catalyzes the oxidation of Fe(II) to Fe(III). Ferroxidase activity is assayed and characterized by coupling the oxidation with the binding of Fe(III) to transferrin. The initial rate of Fe(II) oxidation is dependent on apoferritin and initial Fe(II) concentration but independent of transferrin concentration. The ferroxidase activity is inhibited by Zn(II). Ferritins with varying loads of iron have the same ferroxidase activity level. It is suggested that the described oxidation process represents the initial step of iron deposition in apoferritin. Since transferrin can intercept Fe(III) before it is deposited in apoferritin, active sites for Fe(II) oxidation must be on or near the surface of apoferritin. This finding is contrary to the current view of apoferritin-catalyzed oxidation of Fe(II) which places active sites in the channels to the core or inside the central core.
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PMID:Iron incorporation into apoferritin. The role of apoferritin as a ferroxidase. 375 57

Low density lipoproteins are highly sensitive to oxidation by copper salts, and such peroxidation is accompanied by macrophage scavenger receptor recognition. This study shows that fresh human atherosclerotic material (aneurysms and endarterectomies) can contain detectable amounts of redox active iron and copper that is chelatable from tissue homogenates. Such material is often prooxidant towards lipid peroxidation and deoxyribose degradation. Aneurysms and endarterectomies contain ferroxidase 1 activities, whereas only in aneurysms could caeruloplasmin be immunologically detected. Ferroxidase 2 activity, characteristic of a copper-oxidised lipoprotein complex, could not, however, be detected in any of the atherosclerotic samples. A third ferroxidase activity, attributable to xanthine oxidase, was present in several aneurysms and endarterectomies.
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PMID:Prooxidant iron and copper, with ferroxidase and xanthine oxidase activities in human atherosclerotic material. 763 10

High concentrations of total vitamin C have been measured in the plasma of premature infants. At these concentrations ascorbic acid inhibited the ferroxidase activity of caeruloplasmin measured directly in vitro. The degree of inhibition was dependent on the ratio of ascorbic acid: caeruloplasmin. Values for the ratio of vitamin C: caeruloplasmin measured in premature babies would be predicted to inhibit ferroxidase activity by up to at least 80%. Ferroxidase activity measured in the plasma of premature babies increased from birth but was significantly lower than in plasma collected from adults (< 0.001). Plasma ferroxidase activity was correlated with plasma caeruloplasmin concentration and, in premature babies only, showed a negative correlation with the ratio of vitamin C to caeruloplasmin. High levels of vitamin C in premature babies may compromise antioxidant mechanisms and exacerbate oxidant damage.
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PMID:Vitamin C at concentrations observed in premature babies inhibits the ferroxidase activity of caeruloplasmin. 788 48


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