Effect of latent iron deficiency on the levels of iron, calcium, zinc, copper, manganese, cadmium and lead in liver, kidney and spleen of growing rats

Feeding a marginally low iron content diet (18-20 mg iron/kg diet) to weaned (21-day-old) rats for 8 weeks produced a significant decrease in liver non-heme iron (66%, p less than 0.001) but no change in blood hemoglobin. Total iron contents of liver (56%, p less than 0.01), spleen (20%, p less than 0.05), and kidney (19%, p less than 0.05) were also found to decrease along with increased zinc, copper, calcium, manganese lead and cadmium in various organs. The magnitude of alteration of a metal was different in different organs. However, liver was found to be the most affected organ. Two weeks of rehabilitation with iron-sufficient diet (390 mg iron/kg diet) normalized these altered levels.     

Effect of latent iron deficiency on the levels of iron,calcium, zinc,copper, manganese,cadmium and lead in liver,kidney and spleen of growing rats

Summary Feeding a marginally low iron content diet (18–20 mg iron/kg diet) to weaned (21-day-old) rats for 8 weeks produced a significant decrease in liver non-heme iron (66%, p<0.001) but no change in blood hemoglobin. Total iron contents of liver (56%, p<0.01), spleen (20%, p<0.05), and kidney (19%, p<0.05) were also found to decrease along with increased zinc, copper, calcium, manganese lead and cadmium in various organs. The magnitude of alteration of a metal was different in different organs. However, liver was found to be the most affected organ. Two weeks of rehabilitation with iron-sufficient diet (390 mg iron/kg diet) normalized these altered levels.     

Binding of mercury and zinc to cadmium-binding protein in liver and kidney of goldfish (Carassius auratus L.)

Summary Mercury and zinc, besides Cadmium, are incorporated into cadmium-binding protein found in liver and kidney of goldfish. In the liver, the Cd-BP incorporates more zinc (40%) than in the kidney (1.2%), while mercury show similar affinity for the Cd-BP of this two organs (17 and 12% respectively).Contribution No. 1032 of the Biology Programme, Directorate General XII of the Commission of the European Communities.     

The effect of endotoxin on membrane fatty acid composition in BCG-sensitized mice

The effects of endotoxin on mouse liver phospholipid fatty acid composition have been investigated. Administration of endotoxin from Salmonella abortus equi led to a decrease in the polyunsaturated fatty acid content of livers from mice sensitized with Bacille Calmette Guérin (BCG). The content of arachidonic acid fell significantly in both the phosphatidylcholine and phosphatidylinositol fractions whereas in the phosphatidylethanolamine fraction the linoleic acid content was significantly reduced. The polyunsaturated fatty acids were replaced by increased amounts of oleic acid and palmitic acid, leading to a reduction in the polyunsaturated to saturated fatty acid ratio.     

Zinc,copper and selenium in reproduction

Of the nine biological trace elements, zinc, copper and selenium are important in reproduction in males and females. Zinc content is high in the adult testis, and the prostate has a higher concentration of zinc than any other organ of the body. Zinc deficiency first impairs angiotensin converting enzyme (ACE) activity, and this in turn leads to depletion of testosterone and inhibition of spermatogenesis. Defects in spermatozoa are frequently observed in the zinc-deficient rat. Zinc is thought to help to extend the functional life span of the ejaculated spermatozoa. Zinc deficiency in the female can lead to such problems as impaired synthesis/secretion-of (FSH) and (LH), abnormal ovarian development, disruption of the estrous cycle, frequent abortion, a prolonged gestation period, teratogenicity, still-births, difficulty in parturition, pre-eclampsia, toxemia and low birth weights of infants. The level of testosterone in the male has been suggested to play a role in the severity of copper deficiency. Copper-deficient female rats are protected against mortality due to copper deficiency, and the protection has been suggested to be provided by estrogens, since estrogens alter the subcellular distribution of copper in the liver and increase plasma copper levels by inducing ceruloplasmin synthesis. The selenium content of male gonads increases during pubertal maturation. Selenium is localized in the mitochondrial capsule protein (MCP) of the midpiece. Maximal incorporation in MCP occurs at steps 7 and 12 of spermatogenesis and uptake dereases by step 15. Selenium deficiency in females results in infertility, abortions and retention of the placenta. The newborns from a selenium-deficient mother suffer from muscular weakness, but the concentration of selenium during pregnancy does not have any effect on the weight of the baby or length of pregnancy. The selenium requirements of a pregnant and lactating mother are increased as a result of selenium transport to the fetus via the placenta and to the infant via breast milk.     

The effect of endotoxin on membrane fatty acid composition in BCG-sensitized mice

Summary The effects of endotoxin on mouse liver phospholipid fatty acid composition have been investigated. Administration of endotoxin fromSalmonella abortus equi led to a decrease in the polyunsaturated fatty acid content of livers from mice sensitized with Bacille Calmette Guérin (GCG). The content of arachidonic acid fell significantly in both the phosphatidylcholine and phosphatidylinositol fractions whereas in the phosphatidylethanolamine fraction the linoleic acid content was significantly reduced. The polyunsaturated fatty acids were replaced by increased amounts of oleic acid and palmitic acid, leading to a reduction in the polyunsaturated to saturated fatty acid ratio.     

Trace metal requirements in total parenteral nutrition: A theoretical approach by mathematical modeling

Summary A new computer-based approach has been developed to assess the optimal doses of essential trace metal ions which should be included in nutritive mixtures, used in human total parenteral nutrition, to compensate for the ligand-induced losses of these metal ions. An example of application is given for zinc, copper and manganese.     

Die anorganischen Bestandteile des Honigtaues vonMegoura viciae Buckt

Summary In the honeydew ofMegoura viciae Buckt., sucking on the sieve tube sap ofVicia faba, the following cations are present in measurable quantities: potassium (13.0–14.1 mg/ml), sodium (0.04–0.051 mg/ml), magnesium (1.8–2.3 mg/ml) and calcium (0.07–0.09 mg/ml). There are only traces of copper, iron, manganese, zinc, cobalt and molybdenum. Amongst the anions, phosphate was found at 1.9–2.5 and chloride at 0.02–0.05 mg/ml, whereas nitrate and sulphate could not be detected.     

Administration of D-alanine did not cause increase of D-amino acid oxidase activity in mice.

D-amino acid oxidase (DAAO) activity was not altered in the liver and kidney by oral administration of D-alanine to adult mice. The enzyme was apparently not induced by the enteric microflora either, since the enzyme activity in the liver and kidney of germ-free mice was not different from that of specific-pathogen-free mice. The times of appearance of DAAO activity and of free D-amino acids in the kidney were elucidated using suckling mice. DAAO activity started to increase 7 days after birth, and reached almost the adult level by 28 days. The content of free neutral D-amino acids also increased with age, in a similar fashion. A possible conclusion is that the enzyme activity normally increases during this period, to eliminate the free D-amino acids which have increased with age in the suckling mice. Consequently, the administration of D-alanine had no further effect in increasing enzyme activity.     

Administration of D-alanine did not cause increase of D-amino acid oxidase activity in mice

D-amino acid oxidase (DAAO) activity was not altered in the liver and kidney by oral administration of D-alanine to adult mice. The enzyme was apparently not induced by the enteric microflora either, since the enzyme activity in the liver and kidney of germ-free mice was not different from that of specific-pathogen-free mice. The times of appearance of DAAO activity and of free D-amino acids in the kidney were elucidated using suckling mice. DAAO activity started to increase 7 days after birth, and reached almost the adult level by 28 days. The content of free neutral D-amino acids also increased with age, in a similar fashion. A possible conclusion is that the enzyme activity normally increases during this period, to eliminate the free D-amino acids which have increased with age in the suckling mice. Consequently, the administration of D-alanine had no further effect in increasing enzyme activity.     

Hormonal control of manganese transport in the mouse thyroid.

The present study deals with a possible mechanism controlling the transport of manganese (Mn), an essential trace element, from the circulation to the thyroid. Mice were pretreated with propylthiouracil (PTU) or triiodothyronine (T3), and a measurement of the thyroid:serum concentration ratio (T/S) of radioactive manganese (54Mn) was carried out. The T/S of 54Mn was greatly enhanced by PTU, but reduced by T3. Several methods were used to demonstrate that the T/S of 54Mn depends upon the level of thyroid-stimulating hormone (TSH) in the serum. First, bovine TSH was injected into mice; an increase in the T/S resulted. Secondly, serum thyroxine and T3 levels measured by radioimmunoassay (RIA) suggested that PTU produced an increase in serum TSH and T3 a decrease. However, direct measurement of mouse TSH by RIA for rat TSH failed to produce proof of any changes in TSH level, owing to poor cross-reactivity. Taking all the information into account, it is concluded that Mn-transport into the thyroid is controlled by the thyroid state.     

Concurrent occurrence of elevated ketone body and depressed carnitine level in underfed guinea-pigs

Summary Food ingestion of male guinea-pigs was restricted to 10 g/day. Total carnitine content of liver of the underfed animals fell to 3.75 moles per liver (46.1% of control). Serum level of total carnitine was 35.0 nmoles/ml (64.4%) in the underfed animals while they developed high ketonemia, 384.2 nmoles/ml (555.2%). In restricted animals the carnitine levels also decreased in the muscles.     

Clearance of orally administered115mCd from rat tissues

Summary Peak^115mCd levels in the liver, kidneys, spleen and duodenum of the rat, following a single oral dose, fell exponentially. Half-clearance time for^115mCd is highest in the kidney (30 days) followed by the liver (6.8 days), the spleen (5.5 days) and the duodenum (3.5 days).     

Transketolase and 2-oxoglutarate dehydrogenase activities in the brain and liver of the developing rat

Rat brain transketolase showed little change in activity from birth to adulthood, whereas the liver enzyme activity increased in a biphasic way. In both brain and liver, 2-oxoglutarate dehydrogenase activity increased gradually after birth and reached a plateau at 5 weeks of age. A developmental change in thiamin content in the brain was similar to the change in the 2-oxoglutarate dehydrogenase activity, but this was not the case in the liver.     

Hormonal control of manganese transport in the mouse thyroid

The present study deals with a possible mechanism controlling the transport of manganese (Mn), an essential trace element, from the circulation to the thyroid. Mice were pretreated with propylthiouracil (PTU) or triiodothyronine (T₃), and a measurement of the thyroid:serum concentration ratio (T/S) of radioactive manganese (⁵⁴Mn) was carried out. The T/S of⁵⁴Mn was greatly enhanced by PTU, but reduced by T₃. Several methods were used to demonstrate that the T/S of⁵⁴Mn depends upon the level of thyroid-stimulating hormone (TSH) in the serum. First, bovine TSH was injected into mice; an increase in the T/S resulted. Secondly, serum thyroxine and T₃ levels measured by radioimmunoassay (RIA) suggested that PTU produced an increase in serum TSH and T₃ a decrease. However, direct measurement of mouse TSH by RIA for rat TSH failed to produce proof of any changes in TSH level, owing to poor cross-reactivity. Taking all the information into account, it is concluded that Mn-transport into the thyroid is controlled by the thyroid state.     

Transketolase and 2-oxoglutarate dehydrogenase activities in the brain and liver of the developing rat

Summary Rat brain transketolase showed little change in activity from birth to adulthood, whereas the liver enzyme activity increased in a biphasic way. In both brain and liver, 2-oxoglutarate dehydrogenase activity increased gradually after birth and reached a plateau at 5 weeks of age. A developmental change in thiamin content in the brain was similar to the change in the 2-oxoglutarate dehydrogenase activity, but this was not the case in the liver.     

Effect of vitamin A deficiency on the levels of glutathione and glutathione-S-transferase activity in rat lung and liver

Summary Vitamin A deficiency reduces the content of glutathione in liver and lung. Also, glutathione S-transferase activity is decreased significantly in the lung, whereas its activity is increased in the liver.     

Diurnal variations in serum and liver zinc levels throughout the 4-day estrous cycle of the hamster

Summary Diurnal variations of serum zinc level and liver zinc level of the golden hamster were found throughout the 4-day estrous cycle, and on the different days of the cycle, the patterns of fluctuation differed.     

Effects of CO2 exposure on distribution of various forms of iron and copper in guinea-pig tissues

The effects on iron and copper distribution and metabolism of exposure to high levels of CO2 were studied in the guinea-pig. Mature, male animals were placed in an atmosphere of 15% CO2, 21% O2 (balance N2), and sacrificed from 1 h to 1 week thereafter. Total iron and copper concentrations of blood, liver, spleen and bone, as well as concentrations of heme and ferritin iron, were measured together with blood hematocrit, reticulocytes, plasma hemoglobin, plasma ceruloplasmin and copper concentrations. The results show clearly that rapid and sustained red cell damage or hemolysis ensued several h from the start of CO2 treatment. This resulted in loss of iron and copper from the blood, an influx of both elements into liver, spleen and bone, and a rise in plasma ceruloplasmin. Influx of iron into liver and spleen caused an accumulation of ferritin, the main site for iron storage in cells. Following the effect on red cells, there was an accumulation of heme iron, and a decreased hematocrit, best explained by a depressed activity of the reticuloendothelial and erythropoietic systems. A period of adaptation succeeded these events, in which all blood parameters and most tissue values returned to normal, despite the continuing presence of high CO2. The only changes not reversed were the elevations in liver, spleen and bone iron stores. These remained high, with a net accumulation of greater than 2 mg iron, or 3-4 times more than originally present. The results indicate that at least in the guinea-pig, high CO2 exposure results in red cell damage and other events leading to an accumulation of additional iron in the body; also, that iron accumulated as ferritin and hemosiderin in liver and spleen may not be readily available to restore blood hemoglobin concentrations on an acute basis.     

Zinc binding to peptide analogs of the structural zinc site in alcohol dehydrogenase: Implications for an entatic state

Zinc binding to the peptide replica and analogs to residues 93–115 of horse liver alcohol dehydrogenase (ADH) was examined by competition of the peptides and the chromophoric chelator 4-(2- pyridylazo)resorcinol for zinc and X-ray absorption fine structure analysis of the zinc ligands. In the enzyme, zinc is coordinated by four Cys residues. In the peptide replica, zinc is bound to three Cys and one His residue. A four-Cys zinc coordination is observed only when His is removed, leading to increased zinc stability. ADH crystal structures reveal that the ε-amino group of the conserved residue Lys323 is within H-bond distance of the backbone amide oxygens of residues 103, 105 and 108, likely stabilizing the zinc coordination in the enzyme. The peptide data thus indicate structural strain and increased energy in the zinc-binding site in the protein, characteristic of an entatic state, implying a functional nature for this zinc site. Received 3 July 2008; received after revision 11 August 2008; accepted 1 September 2008