Abnormal porphyrin profile in mussels exposed to low concentrations of cadmium in an experimental Precambrian Shield lake

1995 ◽  
Vol 52 (6) ◽  
pp. 1286-1293 ◽  
Author(s):  
G. Chamberland ◽  
D. Bélanger ◽  
N. Larivière ◽  
L. Vermette ◽  
J. F. Klaverkamp ◽  
...  
Keyword(s):  
Protoporphyrin Ix ◽  
Fluorescence Analysis ◽  
Uroporphyrinogen Decarboxylase ◽  
Elliptio Complanata ◽  
Northwestern Ontario ◽  
Iron Salts ◽  
Low Concentrations ◽  
Iron Deficient ◽  
Potential Applications ◽  
Anodonta Grandis

Seven porphyrins previously suggested as biomarkers of chemical stress in mammals were identified and quantified in the freshwater mussels Elliptio complanata and Anodonta grandis grandis. Uroporphyrin, heptacarboxyporphyrin, hexacarboxyporphyrin, pentacarboxyporhyrin, coproporphyrin and protoporphyrin IX were determined using a method based on esterification of carboxylic acid moieties with BF3-methanol, extraction of the derivatives in chloroform, and HPLC–fluorescence analysis. Porphyrin profiles were compared in reference mussels sampled from nonpolluted lakes versus mussels exposed to 100 μg Cd/L in iron deficient conditions in the laboratory for 1 month or 54–177 ng Cd/L for 4–5 years in an experimental lake (northwestern Ontario, ELA, lake 382). The levels of protoporphyrin and mesoporphyrin were markedly elevated in specimens exposed to iron/salts deficiency and 100 μg Cd/L. In mussels sampled from lake 382, abnormal alterations in the relative proportions of uroporphyrin to heptacarboxyporphyrin, heptacarboxy- to meso-porphyrin, heptacarboxy- to proto-porphyrin, coproporphyrin to mesoporphyrin, and copro- to proto-porphyrin were consistent with a cadmium-mediated response. Thus, differences in the relative proportions of porphyrins, especially those associated with the accumulation of heptacarboxyporphyrin, indicate that Cd may be inhibiting uroporphyrinogen decarboxylase, suggesting potential applications of mussels' porphyrin profile as an ecotoxicological biomarker for Cd and possibly other metals.

A Quantitative Study of the Absorption of Food Iron in Infants and Children

PEDIATRICS ◽  
1958 ◽  
Vol 22 (2) ◽  
pp. 258-258
Keyword(s):  
Iron Deficiency ◽  
Ferrous Iron ◽  
Daily Intake ◽  
Infants And Children ◽  
Deficiency Anemia ◽  
Normal Children ◽  
Iron Salts ◽  
Fundamental Information ◽  
Iron Deficient ◽  
In Infants And Children

These papers contain much fundamental information concerning the prevention and treatment of iron deficiency anemia in infants and children. Normal children absorb an average of about 10% of the iron in natural foods and commercially-prepared infant cereals supplemented with iron. Daily intake of iron by an infant receiving a diet which includes optimal amounts of iron-containing foods may be sufficient to meet the iron requirements of the first 18 months of life unless the infant is born with suboptimal stores of iron, suffers blood loss or is born prematurely. Such a hypothetical infant is probably not representative of a large segment of the population. The authors suggest that more data is needed on the results of giving adequate supplemental iron during infancy to determine whether the hematologic values in infancy may be made to correspond more closely to adult values. Based on the finding of the previous paper that iron supplementation of the diets of many infants may be desirable, studies were undertaken to evaluate the absorption of iron salts by normal and anemic children. Twelve to fifteen percent of a 30 mg dose of ferrous iron given once or twice a day was absorbed by normal children. Iron deficient infants absorb more ferrous iron than do normal infants. The variability between individuals in absorption of food iron and supplemental iron are discussed along with consideration of the dosage of iron salts to be employed in treatment. The authors state that as no investigations have established the desirability of increasing the normal hematologic values of infants beyond their customary levels of 11 to 13 gm/100 ml, indiscriminate supplementation of normal infants' diets is not recommended. Therapetmtic iron is indicated only if specific evidence of iron deficiency exists and the widespread use of mixtures containing several hematopoietic agents is deplored.

Formation of Hydroxyl Radicals from Hydrogen Peroxide and Iron Salts by Superoxide- and Ascorbate-Dependent Mechanisms: Relevance to the Pathology of Rheumatoid Disease

1983 ◽  
Vol 64 (6) ◽  
pp. 649-653 ◽  
Author(s):  
D. A. Rowley ◽  
B. Halliwell
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Hydroxyl Radicals ◽  
Oxygen Radicals ◽  
Rheumatoid Disease ◽  
Iron Salts ◽  
Low Concentrations ◽  
Short Period ◽  
Generating System

1. Superoxide and hydrogen peroxide are formed by activated phagocytes and react together in the presence of iron salts to form the hydroxyl radical, which attacks hyaluronic acid. Ascorbic acid also interacts with hydrogen peroxide and iron salts to form hydroxyl radical in a reaction independent of superoxide. Since iron salts, ascorbate and activated phagocytes are present in the rheumatoid joint, experiments were designed to see whether ascorbate-dependent or superoxide-dependent formation of hydroxyl radicals would be more important in vivo. 2. in the present study, addition of ascorbate to a superoxide-generating system at concentrations of 100 μmol/l provoked a superoxide-independent formation of hydroxyl radicals for a short period. Lower concentrations of ascorbate did not do this. It is therefore suggested that the superoxide-dependent reaction is probably more important. 3. It is further suggested that destruction of ascorbate by oxygen radicals formed by activated phagocytes accounts for the previously reported low concentrations of this compound in the serum and synovial fluid of rheumatoid patients.

Depth distributions determined with SCUBA, and associated studies of the freshwater unionid clams Elliptio complanata and Anodonta grandis in Lake Bernard, Ontario

1978 ◽  
Vol 56 (8) ◽  
pp. 1654-1663 ◽  
Author(s):  
Arthur W. Ghent ◽  
Robert Singer ◽  
Lucinda Johnson-Singer
Keyword(s):  
Threshold Effect ◽  
Sand Wave ◽  
Low Density ◽  
Soft Substrate ◽  
Elliptio Complanata ◽  
Plot Sampling ◽  
Deep Water Species ◽  
Regression Relations ◽  
Anodonta Grandis ◽  
Water Species

Underwater circular-plot sampling showed Elliptio complanata to be confined to the hard-sand, wave-swept shallows, on which the heavy shell and narrow ventral angle of this species permit it to retain a footing. The E. complanata population lay shoreward of 4 m, mostly at depths of 2.5 m or less. A shoreward, low-density extension of the Anodonta grandis population overlaps that of E. complanata, but the A. grandis population extends lakeward to depths of 13–14 m, where its lightweight shell and wide ventral angle permit it to sit on the soft, unconsolidated silt substrate. A blanket of 10 cm or more of this soft substrate has accumulated in Lake Bernard at depths of 6 m or more, beyond the disturbance of surface waves. Specimens taken from these greater depths were markedly stunted, but such stunting was shown to be a progressive phenomenon, increasing with greater depth, rather than a sudden threshold effect at any particular depth. Regression relations among length, height, obesity, and weight of A. grandis shells were the same from all depths. The speculation is advanced that A. grandis may have evolved primarily as a deep-water species.

Macrocyclic intermediates in the biosynthesis of porphyrins

1976 ◽  
Vol 273 (924) ◽  
pp. 191-206 ◽  
Keyword(s):  
High Pressure ◽  
Acetic Acid ◽  
Total Synthesis ◽  
Methyl Esters ◽  
Protoporphyrin Ix ◽  
Acid Group ◽  
Spectroscopic Methods ◽  
Uroporphyrinogen Decarboxylase ◽  
Abnormal Metabolism ◽  
Chicken Erythrocytes

The hepta-, hexa- and penta-carboxylic porphyrins found in the faeces of rats poisoned with hexachlorobenzene have been separated by high-pressure liquid chromatography and characterized largely by spectroscopic methods. Their structures were confirmed by total synthesis, as part of a programme in which eleven of the fourteen hepta-, hexa- and penta-carboxylic porphyrins derived from uroporphyrin III have now been synthesized as their methyl esters. The four isomeric heptacarboxylic and three of the pentacarboxylic porphyrinogens have been incubated with haemolysates of chicken erythrocytes, and they are all converted into protoporphyrin IX but at different rates. On the basis of this and other evidence we conclude that the decarboxylation of uroporphyrinogen III to coproporphyrinogen III is a stepwise process taking place by a preferred pathway (both in normal and abnormal metabolism) ; the acetic acid groups are decarboxylated in a sequential clockwise fashion starting with that on the D ring and followed by those on the A, B and C rings. In the poisoned rats the uroporphyrinogen decarboxylase enzyme (or group of enzymes) is probably partially inhibited and the pentacarboxylic porphyrinogen with an acetic acid group on ring C accumulates. The latter is then transformed by a side pathway into dehydroisocoproporphyrinogen and thence into dehydroisocoproporphyrin and its congeners.

Aggregation of zinc tetraphenylporphyrin characterized by ensemble and single-molecule fluorescence spectroscopy

2011 ◽  
Vol 89 (2) ◽  
pp. 122-129 ◽  
Author(s):  
Jaclyn A. O’Brien ◽  
Yin Lu ◽  
Emma N. Hooley ◽  
Kenneth P. Ghiggino ◽  
Ronald P. Steer ◽  
...  
Keyword(s):  
Single Molecule ◽  
Fluorescence Emission ◽  
Blue Shift ◽  
Water Soluble ◽  
Annihilation Process ◽  
Single Molecule Fluorescence ◽  
Low Concentrations ◽  
Single Molecule Fluorescence Spectroscopy ◽  
Potential Applications ◽  
Significant Blue Shift

The aggregation of metalloporphyrins is believed to play a crucial role in the excited-state annihilation process known as triplet–triplet annihilation, which in turn has significant potential applications in photon upconversion schemes. In this work, the propensity of the water-soluble metalloporphyrin zinc (II) meso-tetra(4-sulfonatophenyl)porphine to undergo aggregation when adsorbed to glass cover slips was investigated by single-molecule fluorescence microscopy. In proof-of-principle experiments, it was demonstrated (1) that individual molecules of the metalloporphyrin can be directly visualized in spite of their very weak fluorescence emission, and (2) that at low concentrations (10−8 mol/L), the molecule has a strong tendency to form multimolecular aggregates. A subset of the multimolecular aggregates shows a significant blue-shift in fluorescence emission, though at present the precise nature of the molecular aggregates remains unclear.

scholarly journals Role of transferrin in determining internal iron distribution

Blood ◽  
1977 ◽  
Vol 49 (6) ◽  
pp. 957-966
Author(s):  
P Pootrakul ◽  
A Christensen ◽  
B Josephson ◽  
CA Finch
Keyword(s):  
Isotope Ratio ◽  
Hepatic Uptake ◽  
The Other ◽  
Iron Salts ◽  
Iron Deficient ◽  
Loading And Unloading ◽  
The Mean

The behavior in vivo of transferrin in loading and unloading iron from its two sites was examined in rats. Radioiron entering the plasma from the gastrointestinal tract in iron-deficient, normal and iron-loaded rats did not differ in its subsequent tissue distribution between erythroid marrow and liver of normal recipients from a second isotope added to the same plasma in vitro. Loading studies in vitro were then carried out employing a reticulocyte incubation model designed to place one isotope predominantly on one site of transferrin, more available to the erythron, and the second isotope on the other site, more available to the liver. In 15 groups of animals in which 3 different iron salts were employed to load transferrin with iron, the mean isotope ratio in the erythron was 1.03 (+/-0.06 SD) and the mean liver ratio was 0.75 (+/-0.21 SD). It was found that the incubation of plasma with reticulocytes resulted in contamination of the plasma by radioactive hemoglobin. After allowance was made for hepatic uptake of radiohemoglobin in the 13 groups in which proper correction could be made, the isotope ratio in the liver became 0.97 (+/-0.17 SD). It is concluded that iron atoms from the two sites of transferrin have similar tissue distributions in vivo in the experimental situations examined.

scholarly journals Kraft Lignin Conversion into Energy Carriers under the Action of Electromagnetic Radiation

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
P. Zharova ◽  
O. V. Arapova ◽  
G. I. Konstantinov ◽  
A. V. Chistyakov ◽  
M. V. Tsodikov
Keyword(s):  
Electromagnetic Radiation ◽  
Microwave Radiation ◽  
Sharp Increase ◽  
Kraft Lignin ◽  
Energy Carriers ◽  
Iron Salts ◽  
Low Concentrations

In this work, it was found that the deposition of iron salts (iron acetate) on kraft lignin at extremely low concentrations of 0.1 wt.% leads to a sharp increase in the absorbing capacity of microwave radiation by kraft lignin at its power of 1 kW and the conversion of kraft lignin to a hydrogen-containing gas with the degree of hydrogen extraction, reaching 90% based on the hydrogen contained in the kraft lignin. It has been established that the deposition of metals (Fe and Ni) on kraft lignin allows one to directionally change the selectivity of the process of its destruction under the influence of microwave radiation, which makes it possible to classify the process as plasmacatalytic. The results obtained make it possible to minimize the amount of catalyst used and propose an efficient way of producing hydrogen from kraft lignin waste.

The Ratio of Erythrocyte Zinc-Protoporphyrin to Protoporphyrin IX in Disease and its Significance in the Mechanism of Lead Toxicity on Haem Synthesis

1998 ◽  
Vol 35 (3) ◽  
pp. 422-426 ◽  
Author(s):  
Joanna C Nelson ◽  
Marie Westwood ◽  
K R Allen ◽  
K E Newton ◽  
J H Barth
Keyword(s):  
Iron Deficiency ◽  
Protoporphyrin Ix ◽  
Lead Toxicity ◽  
Normal Subjects ◽  
Zinc Protoporphyrin ◽  
Mechanism Of Formation ◽  
Erythropoietic Protoporphyria ◽  
Iron Deficient ◽  
Significant Difference ◽  
Exposed Workers

Protoporphyrin and zinc-protoporphyrin were measured in the erythrocytes of normal subjects, workers exposed to lead and patients with iron deficiency and erythropoietic protoporphyria (EPP). Results showed significantly higher levels of zinc-protoporphyrin in the lead-exposed workers ( P < 0·0001), patients with iron deficiency ( P < 0·0001) and EPP patients ( P < 0·001) compared with normal subjects. The lead-exposed workers showed the highest levels of zinc-protoporphyrin, which were significantly greater than both the iron-deficient and EPP patients ( P < 0·0001). They also showed a higher ratio of zinc-protoporphyrin to free protoporphyrin compared with normal subjects ( P < 0·0001) but no significant difference in this ratio was found when compared with iron-deficient patients ( P = 0·1). These results are discussed in light of the controversy concerning the mechanism of formation of zinc-protoporphyrin in lead exposure.

RNA silencing of the mitochondrial ABCB7 transporter in HeLa cells causes an iron-deficient phenotype with mitochondrial iron overload

Blood ◽  
2006 ◽  
Vol 109 (8) ◽  
pp. 3552-3559 ◽  
Author(s):  
Patrizia Cavadini ◽  
Giorgio Biasiotto ◽  
Maura Poli ◽  
Sonia Levi ◽  
Rosanna Verardi ◽  
...  
Keyword(s):  
Hela Cells ◽  
Citrate Synthase ◽  
Protoporphyrin Ix ◽  
Fold Increase ◽  
Mitochondrial Enzymes ◽  
Mitochondrial Superoxide ◽  
Iron Deficient ◽  
Mitochondrial Iron ◽  
Reduced Activity ◽  
Mitochondrial Superoxide Dismutase

Abstract X-linked sideroblastic anemia with ataxia (XLSA/A) is caused by defects of the transporter ABCB7 and is characterized by mitochondrial iron deposition and excess of protoporphyrin in erythroid cells. We describe ABCB7 silencing in HeLa cells by performing sequential transfections with siRNAs. The phenotype of the ABCB7-deficient cells was characterized by a strong reduction in proliferation rate that was not rescued by iron supplementation, by evident signs of iron deficiency, and by a large approximately 6-fold increase of iron accumulation in the mitochondria that was poorly available to mitochondrial ferritin. The cells showed an increase of protoporphyrin IX, a higher sensitivity to H2O2 toxicity, and a reduced activity of mitochondrial superoxide dismutase 2 (SOD2), while the activity of mitochondrial enzymes, such as citrate synthase or succinate dehydrogenase, and ATP content were not decreased. In contrast, aconitase activity, particularly that of the cytosolic, IRP1 form, was reduced. The results support the hypothesis that ABCB7 is involved in the transfer of iron from mitochondria to cytosol, and in the maturation of cytosolic Fe/S enzymes. In addition, the results indicate that anemia in XLSA/A is caused by the accumulation of iron in a form that is not readily usable for heme synthesis.

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