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Query: UMLS:C0240066 (iron deficiency)
 7,156 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The measurement of erythrocyte zinc protoporphyrin (ZPP) with a hematofluorometer is known to be a simple and cost-effective method to screen iron deficiency and lead poisoning. We measured ZPP on blood samples from 201 children suffering from various diseases, which revealed that ZPP has better sensitivity and specificity for identifying iron deficiency than serum ferritin and percent transferrin saturation. ZPP levels in various anemias were also measured. ZPP rose markedly (> 200 mumol/mol heme) in untreated iron deficiency anemia and returned to normal in 3-4 months since the initiation of iron therapy. Moderate elevation of ZPP was observed in acute leukemia (at onset and during induction therapy), MDS, aplastic anemia and some other anemic conditions. These findings suggest that erythrocyte ferrochelatase may be unexpectedly affected in anemias even except lead poisoning.
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PMID:[The measurement of erythrocyte zinc protoporphyrin/heme ratio in various anemias in childhood]. 143 41

The effects of iron deficiency and iron overloading on the mitochondrial enzymes involved in heme synthesis were studied in rat livers. The in vitro activities of several of the enzymes in this pathway were differentially influenced by the in vivo iron status of the animals. delta-Aminolevulinic acid synthase was slightly increased in iron-overloaded animals, but remained normal in iron-deficient animals (0.58 +/- 0.09, 0.91 +/- 0.19 and 0.61 +/- 0.12 nmol delta-aminolevulinic acid/mg per h). Copro- and protoporphyrinogen oxidase activities were increased (20 and 60% above controls) in iron-deficient animals. In contrast, coproporphyrinogen oxidase was decreased by 20%, while protoporphyrinogen oxidase remained unchanged in iron-overloaded rats. These variations of activities were not due to changes in the affinity of these enzymes toward their substrates, as coporphyrinogen had the same Km in each case (0.62 +/- 0.05 M) as did protoporphyrinogen (0.22 +/- 0.035 M). Thus, the Km did not vary with the treatment received by the animals. Ferrochelatase activity was measured by both the pyridine hemochromogen method and by measurement of zinc protoporphyrin with endogenous zinc as substrate. In all cases, ferrochelatase was found to be able to synthesize zinc protoporphyrin with endogenous zinc as substrate. However, the apparent Km of zinc chelatase for protoporphyrin was significantly different in the three groups of animals with Km,appProto, app = 2.4 +/- 0.1 10(-7), 4 +/- 0.3 10(-7) and 9.10 +/- 0.05 10(-7) M in iron-overloaded, control and iron-deficient animals, respectively. When ferrochelatase activity was measured by pyridine hemochromogen, identical results were observed in iron-deficient and control animals but decreased by 45% in iron-overloaded animals. The mitochondrial heme content was also decreased by 40% in iron-overloaded rats but unchanged in either iron-deficient or control rats.
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PMID:Effects of iron deficiency and chronic iron overloading on mitochondrial heme biosynthetic enzymes in rat liver. 395 59

The character and pathogenesis of hemoglobin deficit (gene symbol, hbd), an autosomal recessive trait in the mouse, were studied. The main hematological features of hemoglobin deficit are anemia, red cell hypochromia and microcytosis, and reticulocytosis. The absence of raised fecal urobilinogen excretion and frank hyperbilirubinemia and bilirubinuria suggests that excess hemolysis is not the primary cause of the anemia. The raised plasma iron concentration and the failure of the anemia to respond to parenteral iron treatment indicate that the anemia is not due to iron deficiency. The absence of siderocytes and sideroblasts suggests that anemia is probably not due to ferrochelatase deficiency. Thalassemia is excluded by the finding of balanced reticulocyte globin chain synthesis. The markedly elevated levels of free red cell protoporphyrin taken together with the other findings already noted suggest that the anemia of hemoglobin deficit is due to a defect in the erythroid cell iron procurement mechanisms leading in turn to diminished heme and hemoglobin synthesis.
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PMID:Hemoglobin deficit: an inherited hypochromic anemia in the mouse. 396 Aug 59

Elevation of zinc protoporphyrin (ZPP) levels in the blood has served as an indicator of lead poisoning and iron deficiency anemia for many years. We have discovered that sublethal doses of whole body irradiation with x-rays also elevates ZPP 2-3-fold over normal levels. The ZPP level does not begin to increase until days 12-14 postirradiation and peaks between days 18 and 20 before returning to normal levels between days 28 and 35. Increasing the radiation dose delays the onset of the rise in ZPP, but does not affect the magnitude of the elevation. At lethal doses, ZPP elevation is not observed. Neither of the two previously described mechanisms that cause elevations of ZPP, namely iron deficiency and inhibition of ferrochelatase, are responsible for the radiation-induced elevation of ZPP. The elevation of ZPP appears to be correlated with the recovery of the hematopoietic system from radiation injury.
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PMID:The elevation of blood levels of zinc protoporphyrin in mice following whole body irradiation. 632 27

The diagnostic usefulness of bone marrow hemosiderin, serum ferritin, transferrin saturation, mean corpuscular volume (MCV) and red cell protoporphyrin (EPP) in the evaluation of iron status in patients on chronic hemodialysis was studied in 39 subjects. The correlation between serum ferritin and the number of transfusions received per month was slightly higher (r = 0.717; p less than 0.001) than the correlation between bone marrow hemosiderin and transfusions (r = 0.685; p less than 0.01). Serum ferritin was useful in identifying subjects with both increased or reduced iron stores. In contrast, transferrin saturation could only be used for indicating iron overload. MCV for indicating iron deficiency, and EPP was not useful in either case. The abnormal increase of EPP in chronic uremia has not been previously described. It is unrelated to iron deficiency and is most probably explained by the known reduction in red cell ferrochelatase activity associated with chronic uremia. Serum ferritin is clearly the most useful diagnostic aid for assessing iron stores in patients on chronic hemodialysis. Whether ferritin is also the best predictor of response to iron therapy, cannot be determined on the basis of the present data.
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PMID:Evaluation of iron status in patients on chronic hemodialysis: relative usefulness of bone marrow hemosiderin, serum ferritin, transferrin saturation, mean corpuscular volume and red cell protoporphyrin. 663 60

We have studied the iron metabolism in nine patients with erythropoietic protoporphyria (EPP) and three patients with sideroblastic anaemia (SA). All, except one EPP patient were iron deficient. The SA patients had a secondary haemochromatosis. The bone marrow aspirates of patients with SA and also three patients with EPP had a high incidence of ring sideroblasts. Ultrastructural examination of the bone marrow consistently showed finely dispersed electron-dense deposits localized in mitochondria of erythroblasts in all patients with EPP and SA. Mitochondrial electron energy-loss spectroscopy (EELS) indicated identical iron compounds in erythroblasts of all EPP and SA patients. These findings indicate that the mitochondrial iron utilization is disturbed in EPP and SA. The observation of mitochondrial iron deposition in erythroblasts in EPP and SA suggests that this failure is not of pathognomonic value for diagnosis of SA, but is apparently the result of an inefficient haem synthesis, in EPP due to a defective ferrochelatase. The mitochondrial iron deposition does not depend on the iron status (iron overload or iron deficiency) of the EPP patient.
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PMID:Accumulation of iron in erythroblasts of patients with erythropoietic protoporphyria. 846 22

In iron deficiency and lead poisoning, the enzyme ferrochelatase catalyzes the incorporation of zinc, instead of iron, into protoporphyrin IX, resulting in the formation of zinc protoporphyrin (ZPP). In healthy blood donors, there is a good inverse correlation between serum ferritin and ZPP levels. In renal failure patients and in patients with anemia caused by a variety of chronic disorders, two different types of iron deficiency are found: (a) absolute iron deficiency and (b) relative, or functional, iron deficiency. The latter occurs when iron, despite adequate stores, is not delivered rapidly enough to the erythroblasts. ZPP is not only indicative of absolute iron deficiency, but it is also, for now, the best indicator of iron-deficient erythropoiesis, along with the percentage of hypochromic red blood cells. By contrast, serum ferritin and transferrin saturation may not adequately assess functional iron deficiency. Elevated ZPP levels in renal failure patients can be caused by different pathogenetic mechanisms, such as chronic inflammatory disease, lead poisoning, and the presence of uremic factors, all of which could potentially inhibit heme biosynthesis. However, ZPP levels do not consistently predict an erythropoietic response to iron supplementation in maintenance hemodialysis patients, and thus, iron overload during i.v. iron supplementation cannot be detected by measuring ZPP.
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PMID:Erythrocyte zinc protoporphyrin. 1008 87

Some enzymes and intermediates of heme synthesis were determined in blood and urine of 26 women with severe iron deficiency anemia (IDA). Erythrocyte free protoporphyrin was almost doubled and delta-aminolevulinate dehydrase significantly raised. But urinary excretion of delta-aminolevulinic acid and reticulocyte ferrochelatase were significantly reduced in iron deficiency anemia. Hence these could serve as useful indices of iron deficiency and consequent anemia.
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PMID:Some biochemical changes in heme synthesis in iron deficiency. 1121 7

Heme deficiency was studied in young and old normal human fibroblasts (IMR90). Regardless of age, heme deficiency increased the steady-state level of oxidants and lipid peroxidation and sensitized the cells to fluctuations in intracellular Ca(2+). Heme deficiency selectively decreased the activity and protein content of mitochondrial complex IV (cytochrome c oxidase) by 95%, indicating a decrease in successful assembly. Complexes I-III and catalase remained intact under conditions of heme deficiency, whereas ferrochelatase was up-regulated. Complex IV is the only hemeprotein in the cell that contains heme a, which may account for its susceptibility. The rate of removal and assembly of complex IV declines with age. These findings are relevant to worldwide iron deficiency in women and children and to an age-related decline in complex IV in Alzheimer's disease patients.
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PMID:Heme deficiency selectively interrupts assembly of mitochondrial complex IV in human fibroblasts: revelance to aging. 1159 32

Patients with deficiency in ferrochelatase (FECH), the last enzyme of the heme biosynthetic pathway, experience a painful type of skin photosensitivity called erythropoietic protoporphyria (EPP), which is caused by the excessive production of protoporphyrin IX (PPIX) by erythrocytes. Controversial results have been reported regarding hematologic status and iron status of patients with EPP. We thoroughly explored these parameters in Fechm1Pas mutant mice of 3 different genetic backgrounds. FECH deficiency induced microcytic hypochromic anemia without ringed sideroblasts, little or no hemolysis, and no erythroid hyperplasia. Serum iron, ferritin, hepcidin mRNA, and Dcytb levels were normal. The homozygous Fechm1Pas mutant involved no tissue iron deficiency but showed a clear-cut redistribution of iron stores from peripheral tissues to the spleen, with a concomitant 2- to 3-fold increase in transferrin expression at the mRNA and the protein levels. Erythrocyte PPIX levels strongly correlated with serum transferrin levels. At all stages of differentiation in our study, transferrin receptor expression in bone marrow erythroid cells in Fech(m1Pas) was normal in mutant mice but not in patients with iron-deficiency anemia. Based on these observations, we suggest that oral iron therapy is not the therapy of choice for patients with EPP and that the PPIX-liver transferrin pathway plays a role in the orchestration of iron distribution between peripheral iron stores, the spleen, and the bone marrow.
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PMID:Increased plasma transferrin, altered body iron distribution, and microcytic hypochromic anemia in ferrochelatase-deficient mice. 1700 76


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