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At least 19 recordsLinked to original sources
PubMed1979

Serum and urinary vanadium of vanadium-exposed workers.

In this investigation the environment of vanadium workers was studied. It was found that low concentrations of vanadium (0.01--0.04 mg/m3) in the air do not correlate with vanadium serum levels or its urinary excretion. The results, however, suggest that values of vanadium in serum and urine samples reflect absorption of vanadium because vanadium could not be detected in the urine of referents. In higher vanadium exposure (0.2--0.5 mg/m3), the concentration in the air inhaled remaining unknown due to the use of dust masks, urinary vanadium excretion and serum vanadium level decreased significantly with exposure-free time.

Air Pollutants↗
PubMed1992

Accumulation of vanadium during embryogenesis in the vanadium-rich ascidian, Ascidia gemmata.

It is a remarkable and previously unrecognized fact that ascidians, which are known to contain high levels of vanadium in their blood cells, begin to accumulate vanadium during embryogenesis. This study revealed that the accumulation starts quite dramatically 2 wk after fertilization, and 2 mo later, the amount of vanadium in larvae is 600,000 times higher than that in the unfertilized egg. These results were obtained by neutron activation analysis, a highly sensitive method for determining levels of vanadium, in the Ascidia gemmata, the ascidian that contains the highest known levels of vanadium and accumulates vanadium at 150 mM in its blood cells, a concentration that corresponds to 4,000,000 times the concentration in seawater.

Animals↗
PubMed1977

The role of vanadium in gree plants. II. Vanadium in green algae--two sites of action.

Cells of Chlorella pyrenoidosa, derived from vanadium free agar slants, respond with great sensitivity to microamounts of vanadium, added as NH4VO3 to autotrophic liquid cultures. Between 0.01 and 1 microgram V per litre nutrient medium (2-10(-10)-2-10(-8) g-at/1), the algae respond with a continuous incrase in dry weight. At higher V-concentrations, further enhancement in biomass is accompanied by a additional increase in chlorophyll content. Maximum V-effect on both parameters was found to be at 500 microgram V/1 (10(-5) G-AT/1). Dry weight as well as chlorophyll content of Chlorella are decreased by concentrations above 25 mg V/1; 100 mg V/1 (2-10(-3) g-at/1) stop growth and cause death of the cells. The toxic threshold for the V-content in the algae was determined to be at 150-200 microgram V/g (3-4-10(-6) g-at/g) dry weight. Two different pH-optima for a positive vanadium action on dry weight and chlorophyll biosynthesis were established, the first at pH 7, the other in the range pH 7.5--8. Two sites of vanadium action in green algae are discussed.

Chlorella↗
PubMed1979

Effects of vanadium on the upper respiratory tract of workers in a vanadium factory. A macroscopic and microscopic study.

An epidemiologic cross-sectional case-history study on the injurious effects of vanadium was carried out among the workers of a vanadium factory. The upper respiratory tract of 63 male workers exposed to vanadium dust was examined macroscopically and microscopically, and the findings were compared with those of a reference group of workers who were exposed to inert dust only. The groups compared were of similar ages and had similar smoking habits. Nasal smears and sputum cells were studied microscopically, and biopsies for histological study were taken from the nasal mucosa. The biopsies from the vanadium workers showed a significant increase in the number of plasma and round cells, and the histological picture was almost characteristic. There were no increased numbers of secretion eosinophils or other signs indicative of allergic inflammation.

Age Factors↗
PubMed1992

Desferrioxamine enhances the reactivity of vanadium (IV) and vanadium (V) toward ferri- and ferrocytochrome c.

Ligands, especially desferrioxamine, affect the rate at which vanadium reduces or oxidizes cytochrome c. Whether reduction or oxidation occurs, and how fast, depends on the nature of the ligand, the state of reduction of the vanadium, the pH (6.0, 7.0, or 7.4), and the availability of oxygen. In general, oxidation of ferrocytochrome c was favored by (1) low pH, (2) an oxidized state of the vanadium, (3) the presence of oxygen, and (4) more strongly binding ligands (desferrioxamine much greater than histidine = ATP greater than EDTA greater than albumin greater than aquo). Thus, at pH 6.0, desferrioxamine accelerated the V(V)-catalyzed ferrocytochrome c oxidation 160-fold aerobically, and 3500-fold anaerobically. In general, strongly binding ligands slowed oxidations, especially at higher pH. Desferrioxamine was unique among the five ligands in that it not only accelerated oxidation of ferrocytochrome c at pH 6.0, but at pH 7.4 the redox balance shifted to the point where it paradoxically reduced ferricytochrome c. V(V) is an improbable electron donor, but desferrioxamine will reduce cytochrome c, and V(V) accelerates this process. Oxidation of cytochrome c by V(V):desferrioxamine was faster anaerobically, and reduction by V(IV):desferrioxamine was faster aerobically. Although V(V) did not oxidize ferrocytochrome c at pH 7.4, V(IV) did, provided oxygen and desferrioxamine were both present. V(IV):desferrioxamine almost completely reduced ferricytochrome c, and this reduction was followed by a slow, progressive oxidation. This latter oxidation of cytochrome c is mediated by active species generated in the reaction between V(IV):desferrioxamine and oxygen, because none of these reagents alone can induce oxidation at a comparable rate. The mediating species were transient, and generated in reactions with oxygen.(ABSTRACT TRUNCATED AT 250 WORDS)

Catalase↗
PubMed1979

[Field tests carried out to determine the occupational exposure to vanadium (author's transl)].

In a metallurgic plant we analysed blood samples, urine and finger-nails of 54 workers exposed to vanadium. On the basis of orientating dust measurements it can be assumed that the results obtained were, as a rule, clearly lower than the MAC values for vanadium pentoxide dust. The median vanadium concentration in whole-blood was 2.9 micrograms/l. This indicates that the exposed persons differ significantly from the control group. The median vanadium concentration measured in urine was 37.8 micrograms/l. This means that there is a significant difference in comparison with the control group (0.8 micrograms/l). In order to obtain values of greater reliability, the vanadium concentration resulting from the analysis of spontaneous urine samples was to be referred to the creatinine content. Conversion yields a medium vanadium concentration of 33.9 and 0.6 micrograms/g creatinine for the exposed workers and normal persons respectively. The cystine content found in the finger-nails of persons occupationally exposed to vanadium was significantly reduced with respect to the comparative group (8.9 against 9.9 mg cystine per 100 mg finger-nails). Within the groups of persons examined no correlation is found to exist between the cystine content of the finger-nails and the age of the persons, nor between the vanadium concentrations in blood and urine. After a weekend without exposure the vanadium concentrations in blood and urine dropped. In general, this drop was the more pronounced the higher the initial value was. Roughly two to four days after the occupational exposure had ceased, the values dropped to the half of the initial value. Based on the test results available, the vanadium concentrations in blood and urine reflect the extent of an occupational vanadium exposure and are suitable indicators for estimating the potential threat caused by this heavy metal.

Age Factors↗
PubMedDate not supplied

Inhibition by vanadium of sodium and potassium dependent adenosinetriphosphatase derived from animal and human tissues.

Inhibition of adenosinetriphosphatase (ATPase) by vanadium pentoxide (dissolved in water or in sodium hydroxide solution) was studied in microsomal fractions and tissue homogenates of kidney, brain, and heart of several species, including humans (kidney only). In some preparations vanadium was found to be the most potent inhibitor of Na+ + K+ATPase activity so far reported. Concentrations of vanadium causing 50 percent inhibition of Na+ + K+ATPase activity ranged from 6 x 10(-8) to 5 x 10(-7) M in microsomal fractions and from 2 x 10(-7) to 1 x 10(-6) M in tissue homogenates. Renal and cardiac enzymes were more sensitive to vanadium than the brain enzyme, a phenomenon independent of enzyme specific activity. The enzyme in tissue homogenates was more resistant to vanadium than the microsomal enzyme derived from the same tissues, suggesting a presence in tissues of protective agents. Mg2+ ATPase, which contaminated the enzyme preparations to a variable degree, was 1,000-10,000 times more resistant to vanadium than was Na+ + K+ATPase. More detailed studies on the mechanism of inhibition were performed with dog and human kidney enzymes. The reversible nature of the inhibition was suggested by the fact that fractional inactivation of Na+ + K+ATPase by vanadium was independent of enzyme protein concentrations. The inhibitory effect was reduced by Na+ and increased by K+ or Mg2+. ATP alone, but not MgATP, antagonized the inhibition. This could mean that vanadium inhibits the Na+ + K+ATPase at the site activated by Na+, and that ATP protects the enzyme either by binding vanadium or by competing for a mutual receptor on the enzyme. The inhibition was reduced by bovine serum albumin, probably binding vanadium. The inhibition was also diminished by reducing agents, ascorbic acid and citric acid.

Adenosine Triphosphate↗
PubMed1992

Haematological effects of vanadium on living organisms.

Although vanadium has been of great interest for many researchers over a number of years, its biochemical and physiological role is not yet fully clear. There are many papers describing the haematological consequences of its excess in living organisms and most of their data are quoted in this mini-review. The authors of these papers used various laboratory animals, different vanadium compounds, frequently different routes of administration and duration of intoxication. Hence a checklist and comparison of the results are rather difficult. Vanadium reduces the deformability of erythrocytes, and such cells are rather frequently retained in the reticuloendothelial system of the spleen and eliminated faster from the blood stream (Kogawa et al., 1976). Vanadium produces peroxidative changes in the erythrocyte membrane, this leading to haemolysis. Therefore, the depressed erythrocyte count in animals intoxicated with vanadium may be the consequence of both the haemolytic action of vanadium and the shortened time of survival of erythrocytes. Changes of the haem precursor level in blood serum and urine observed in humans exposed occupationally to vanadium suggest an influence of this element on haem synthesis. This problem requires, however, further studies and observations. Changes occurring under the influence of vanadium on the leukocyte system of animals suggest the influence of this element on the resistance of the organism, but the mechanism of the action of vanadium still requires elucidation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1975

Effect of vanadium on growth, chlorophyll formation and iron metabolism in unicellular green algae.

In the presence of vanadium, growth of Scenedesmus obliquus and Chlorella pyrenoidosa was increased five to sixfold as determined by dry weight, when cultured under autotrophic conditions for 7 days. The stimulation by vanadium decreased with increasing stability towards hydrolysis of the iron(III)-compounds added. Pentavalent vanadium (20 mug V/1 as NH4VO3) was able to overcome completely a limited iron-deficiency in the algae following growth in presence of 1.8 - 10(-5) m ferric chloride. Vanadium did not alter the iron uptake into the algal cells. 90% of offered 48V was taken up by Scenedesmus obliquus during 5 days of growth, and 21% thereof were found in the chloroplast fraction. In presence of vanadium, the chlorophyll formation was stimulated in Scenedesmus obliquus. This stimulation by vanadium was found to be light-dependent but occurred to a certain extent in the dark also. The main porphyrin of the yellow mutant 211-11h/20 of Chlorella vulgaris was identified as protoporphyrin-IX. The formation of this compound was stimulated by vanadium within 10 days up to 83%. The role of vanadium in the biosynthesis of chlorophylls is discussed.

Chlorella↗
PubMed1976

The effect of diet on the toxicity of vanadium.

Five experiments were conducted with growing chicks to determine the effectiveness of various materials in modifying the toxicity of vanadium. The toxicity of vanadium (as it is measured by growth depression and mortality) was much greater when vanadium was added to a semipurified diet than when it was added to a practical diet containing natural ingredients. When EDTA was added to diets containing 50 to 200 p.p.m. vanadium, the growth depression was reduced from 22.1% and 75.9% to 8.4% and 36.7% respectively, and the mortality was reduced from 80% to 20% among chicks fed 200 p.p.m. vanadium. The addition of 10% lactose to a diet containing 100 p.p.m. vanadium increased the growth depression from 41% to 76.2% and caused 80% mortality. Chromium added to diets containing 100 and 200 p.p.m. vanadium improved the growth and reduced the mortality.

Animal Feed↗
PubMed1992

Structure and function of vanadium compounds in living organisms.

Vanadium has been recognized as a metal of biological importance only recently. In this mini-review, its main functions uncovered during the past few years are addressed. These encompass (i) the regulation of phosphate metabolizing enzymes (which is exemplified for the inhibition of ribonucleases by vanadate), (ii) the halogenation of organic compounds by vanadate-dependent non-heme peroxidases from seaweeds, (iii) the reductive protonation of nitrogen (nitrogen fixation) by alternative, i.e. vanadium-containing, nitrogenases from N2-fixing bacteria, (iv) vanadium sequestering by sea squirts (ascidians), and (v) amavadine, a low molecular weight complex of V(IV) accumulated in the fly agaric and related toadstools. The function of vanadium, while still illusive in ascidians and toadstools, begins to be understood in vanadium-enzyme interaction. Investigations into the structure and function of model compounds play an increasingly important role in elucidating the biological significance of vanadium.

Animals↗
PubMed1978

Vanadium in foods and in human body fluids and tissues.

Using neutron activation analysis, vanadium was analysed in a range of foods, human body fluids and tissues. On the basis of these results and those of other workers, it was concluded that daily dietary intake amounts to some tens of micrograms. Analysis of body fluids (including milk, blood and excreta) and organs and tissues provided an estimate for the total body pool of vanadium in man of about 100 microgram. Vanadium was not detectable in blood and urine at the level of 0.3 ng/g, while low levels were found in muscle, fat, bone, teeth and other tissues. The relationship between dietary intake to pulmonary absorption is discussed in relation to the occurrence of vanadium in man-made air particulates. The very low levels found in milks and eggs suggest minimal vanadium requirements in growth. The findings are discussed in the light of previous results and also in relation to the possible essentiality of vanadium.

Air↗
PubMed1978

Effects of dietary vanadium in mallard ducks.

Acult mallard ducks fed 0, 1, 10, or 100 ppm vanadyl sulfate in the diet were sacrificed after 12 wk on treatment; tissues were analyzed for vanadium. No birds died during the study and body weights did not change. Vanadium accumulated to higher concentrations in the bone and liver than in other tissues. Concentrations in bones of hens were five times those in bones of drakes, suggesting an interaction between vanadium and calcium mobilization in laying hens. Vanadium concentrations in most tissues were significantly correlated and increased with treatment level. Lipid metabolism was altered in laying hens fed 100 ppm vanadium. Very little vanadium accumulated in the eggs of laying hens.

Animals↗
PubMed1976

The effect of dietary vanadium on fatty acid and cholesterol synthesis and turnover in the chick.

Day-old male, broiler type chicks were used to study the effect of 100 ppm dietary vanadium on fatty acid and cholesterol synthesis and turnover in vivo. After feeding the experimental diets for 4 weeks body weight and liver weight of chicks fed 100 ppm vanadium were significantly less than those of the control chicks and liver total lipid and cholesterol tended to be slightly higher than the levels of the control chicks. [1-14C] Acetate was administered intravenously and the specific activities of plasma and liver total lipid, cholesterol and fatty acid were determined at 0.25, 0.50, 1.0, 4.0, 8.0 and 15.0 hours after the injection. Plasma total lipid and cholesterol were significantly higher than the levels in the control chicks. The rate of incorporation of [1-14C]acetate into plasma and liver total lipid, cholesterol and fatty acid was higher in chicks fed vanadium than the control group at any of the time being tested after the injection. There was a significant increase in the hepatic citrate cleavage enzyme activity among chicks fed 100 ppm vanadium, whereas, there was no significant change in acetate thiokinase activity. Turnover rate of plasma total lipid and fatty acid in vanadium fed chicks was lower than the control. The turnover rate of plasma cholesterol determined by administering [4-14C]cholesterol and periodically measuring the specific activity of plasma cholesterol was higher in chicks fed vanadium than in those fed the basal diet.

ATP Citrate (pro-S)-Lyase↗
PubMed1976

The effect of pharmacological levels of dietary vanadium on the egg production, shell thickness and egg yolk cholesterol in laying hens and coturnix.

The addition of 100 p.p.m. of vanadium to a ration for White Leghorn laying hens caused a significant increase (p less than 0.01) in the egg shell thickness, but did not cause any significant change in the production, egg weight or egg ypok cholesterol content. The addition of 300 p.p.m. of vanadium caused a severe depression in the egg production which was the only symptom of vanadium toxicity to be observed. The addition of 50, 100, 200 or 300 p.p.m. vanadium to the ration of laying coturnix did not cause any significant change in egg production, egg weight, or egg yolk cholesterol content. The addition of the same levels of vanadium to one-day old male coturnix chicks did not cause any significant growth depression or mortality. We suggest that coturnix may be more resistant to vanadium toxicity than chickens.

Animals↗
PubMed1978

Similarity in metabolic patterns of different chemical species of vanadium in the rat.

To gain information about the influence of the oxidation state of vanadium on its metabolic behavior, different 48V-labeled vanadium compounds, such as cationic VO2+(V), VO2+(IV), V3+(III), and anionic V4O12(3-)(V), VS4(3-)(V) species were prepared and intravenously injected into rats. The 48V radioactivity was measured in whole tissues as well as in nuclei, mitochondria, lysosomes, microsomes, and cytosols from liver and kidney homogenates. The distribution of 48V radioactivity between the plasma components was investigated using gel filtration of the 48V-labeled plasma. The findings indicate that there are common pathways of the different chemical forms of vanadium in animals. The similarities are referred to the distribution in different tissues and their intracellular distribution as well as to the transport in the blood, in which 48V was always found in the plasma bound to transferrin. The results obtained tend to exclude a possible influence of the oxidation state of vanadium on its metabolism and support the existence in the body of two mechanisms of conversion of different chemical forms of vanadium ions to one with the same valence.

Animals↗
PubMed1977

Gel filtration analysis of vanadium in Ascidia nigra blood cell lysate.

Fractions from a Sephadex gel filtration of homogenized Ascidia nigra blood cell lysate were analyzed for vanadium by atomic absorption spectroscopy. The results were unaffected by temperature from 4-21 degrees C, and by ionic strength in the range 0.09-1.0 M (NaCl). Appreciable loss of vanadium in the supernatant was experienced above pH 2.2. Experiments at pH 2.1 under anaerobic conditions show that the green chromogen and the vanadium-containing bands elute separately. Under these experimental conditions, the vanadium-containing species is of relatively low (congruent to 1,000) molecular weight.

Animals↗