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Rocha JBT, Saraiva RA, Garcia SC, Gravina FS, Nogueira CW. Aminolevulinate dehydratase (δ-ALA-D) as marker protein of intoxication with metals and other pro-oxidant situations. Toxicol Res (Camb) 2012. [DOI: 10.1039/c2tx20014g] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Fujita H, Nishitani C, Ogawa K. Lead, chemical porphyria, and heme as a biological mediator. TOHOKU J EXP MED 2002; 196:53-64. [PMID: 12498316 DOI: 10.1620/tjem.196.53] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
One of the most well-characterized symptoms of lead poisoning is porphyria. The biochemical signs of lead intoxication related to porphyria are delta-aminolevulinic aciduria, coproporphyrinuria, and accumulation of free and zinc protoporphyrin in erythrocytes. From the 1970s to the early 80s, almost all of the enzymes in the heme pathway had been purified and characterized, and it was demonstrated that delta-aminolevulinic aciduria is due to inhibition of delta-aminolevulinate dehydratase by lead. Lead also inhibits purified ferrochelatase; however, the magnitude of inhibition was essentially nil even under pathological conditions. Further study proved the disturbance of iron-reducing activity by moderate lead exposure. Far different from these two enzymes, lead failed to inhibit purified coproporphyrinogen oxidase, i.e., the mechanism of coproporphyrinuria has not yet been understood. During the 80s to the 90s, the effects of environmental hazards including lead were elucidated through stress proteins, indicating the induction of some heme pathway enzymes as stress proteins. At that time, gene environment interaction was another focus of toxicology, since gene carriers of porphyrias are considered to be a high-risk group to chemical pollutants. Toxicological studies from the 70s to the 90s focused on the direct effect of hazards on biological molecules, such as the heme pathway enzymes, and many environmental pollutants were proved to affect cytosolic heme. Recently, we demonstrated the mechanism of the heme-controlled transcription system, which suggests that the indirect effects of environmental hazards are also important for elucidating toxicity, i.e., the hazards can affect cell functions through such biological mediators as regulatory heme. It is, therefore, probable that toxicology in the future will focus on biological systems such as gene regulation and signal transduction systems.
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Affiliation(s)
- Hiroyoshi Fujita
- Laboratory of Environmental Biology, Hokkaido University School of Medicine, Sapporo 060-8638, Japan.
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Padmaja K, Ramamurthi R, Prasad AR. Inhibitory effect of selenium on enzymes involved in heme biosynthetic pathway in chick embryos. JOURNAL OF ENZYME INHIBITION 1996; 11:1-11. [PMID: 9204391 DOI: 10.3109/14756369609038217] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Effect of different concentrations of selenium (Se) on heme biosynthesis was studied at different developmental stages of chick embryo. The first rate limiting enzyme ALA-synthase (ALA-S; E.C.2.3-1.37) activity was enhanced by selenium, while hepatic and blood ALA-dehydratase activity (ALA-d; E.C.3.2.1.24) was decreased. Hepatic and blood free-sulfhydryl (-SH) group contents were significantly decreased by Se. Further, hepatic aminolevulinic acid (ALA) and total blood porphyrin levels were enhanced and hepatic heme levels were depleted by selenium exposure. Heme biosynthesis was maximally inhibited in the E4 (4th day injected embryos) when compared to later periods.
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Affiliation(s)
- K Padmaja
- Department of Zoology, Sri Venkateswara University, Tirupati, A.P., India
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Chalevelakis G, Bouronikou H, Yalouris AG, Economopoulos T, Athanaselis S, Raptis S. delta-Aminolaevulinic acid dehydratase as an index of lead toxicity. Time for a reappraisal? Eur J Clin Invest 1995; 25:53-8. [PMID: 7705388 DOI: 10.1111/j.1365-2362.1995.tb01526.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
delta-Aminolaevulinic acid dehydratase activity is traditionally accepted as the most sensitive measurable biological index of lead toxicity. We have measured delta-aminolaevulinic acid dehydratase activity and blood lead concentration in 47 healthy controls (A), 42 iron deficient patients (B) and 38 occupationally exposed to lead subjects (C). Blood lead levels [mean (SD)] did not differ between groups A and B [0.51 (0.21) and 0.43 (0.19) mumol L-1, respectively] while those of group C [2.28 (0.56) mumol L-1 were significantly higher (P < 0.001) as compared to the controls. delta-Aminolaevulinic acid dehydratase activity [mean (SD)] was significantly increased [3599 (1909) mumol L-1 h-1] in group B and decreased in group C [1052 (532) mumol L-1 h-1] as compared to the controls [2034 (446) mumol L-1 h-1] (P < 0.001). There was a significantly negative correlation of logarithm of delta-aminolaevulinic acid dehydratase with lead in both groups B (P < 0.05) and C (P < 0.001) but not in group A (P = 0.1). delta-Aminolaevulinic acid dehydratase activity had a high specificity (100%) but a low sensitivity (37%) as an index of toxic lead exposure. According to our data the value of delta-aminolaevulinic acid dehydratase measurement in the diagnosis of lead intoxication is doubtful in cases with low blood lead levels, while in the presence of iron deficiency its reliability is further reduced, since low blood lead levels may be falsely predicted. delta-Aminolaevulinic acid dehydratase activity should be restricted only to monitoring cases with moderate or severe lead poisoning.
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Affiliation(s)
- G Chalevelakis
- Second Department of Internal Medicine-Propaedeutic, University of Athens, School of Medicine, Greece
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Abstract
To gain further insight into the mechanisms by which both granulocyte-macrophage-colony stimulating factor (GM-CSF) and erythropoietin receptors function, we have utilized a GM-CSF erythropoietin hybrid receptor with GM-CSF as the external domain and erythropoietin as the intracellular domain. Results show that the beta common GM-CSF receptor both enhances the affinity binding of GM-CSF to the receptor and plays an important role in signaling through the receptor. A truncated form of the beta common receptor actually acts as a dominant negative regulatory factor.
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Affiliation(s)
- D G Nathan
- Division of Hematology/Oncology, Children's Hospital, Boston, Massachusetts
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Chmielnicka J, Nasiadek M, Lewandowska-Zyndul E. The effect of aluminum chloride on some steps of heme biosynthesis in rats after oral exposure. Biol Trace Elem Res 1994; 40:127-36. [PMID: 7514018 DOI: 10.1007/bf02950786] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Certain disturbances in heme biosynthesis induced by aluminum chloride were examined. The experiment was performed on female rats that received AlCl3 orally at the dose 100 mg Al/kg daily for 21 d. The effects of aluminum on the activity of delta-aminolevulinic acid synthetase (ALA-S), dehydratase (ALA-D), and heme oxygenase (O.H.) were observed on 3, 7, 14, and 21 d in liver and kidneys of rats. Also the activity of ALA-D in blood and the concentration of delta-aminolevulinic acid (ALA-U) in urine were observed. Orally administered aluminum caused increase in the activity of ALA-D in the liver and blood, and parallel decrease of ALA-U in urine (r = -0.85) of rats. Aluminum chloride also induced an increase of ALA-S and O.H. in the liver but not in the kidneys. The changes of the enzymes activity participating in heme biosynthesis after administration of aluminum may be correlated with anemia and iron metabolism in rats.
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Affiliation(s)
- J Chmielnicka
- Medical University of Lodz, School of Pharmacy, Department of Toxicological Chemistry, Poland
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Jaffe EK, Bagla S, Michini PA. Reevaluation of a sensitive indicator of early lead exposure. Measurement of porphobilinogen synthase in blood. Biol Trace Elem Res 1991; 28:223-31. [PMID: 1713045 DOI: 10.1007/bf02990469] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A principal target for the environmental toxin lead (Pb) is porphobilinogen synthase (PBGS), a Zn-metalloenzyme necessary for heme biosynthesis. Measurement of blood Pb inhibited PBGS is the most sensitive indicator of subclinical Pb intoxication, but problems with the assay have diminished its use. This report identifies Pb as a slow acting inhibitor of PBGS. The activity of PBGS could change up to sixfold during an hourlong clinical assay of Pb contaminated blood, and activity is profoundly effected by the presence of serum proteins, such as albumin. When PBGS catalyzed PBG production is allowed to reach a steady state rate, kinetic data on purified PBGS support the hypothesis that Pb inhibition of PBGS results from direct substitution for Zn.
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Affiliation(s)
- E K Jaffe
- Biochemistry Department, University of Pennsylvania School of Dental Medicine, Philadelphia 19104-6002
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Lolin Y, O'Gorman P. An intra-erythrocytic low molecular weight lead-binding protein in acute and chronic lead exposure and its possible protective role in lead toxicity. Ann Clin Biochem 1988; 25 ( Pt 6):688-97. [PMID: 3254111 DOI: 10.1177/000456328802500616] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A low-molecular-weight protein was measured in erythrocytes from workers with chronic and recent lead exposure, with and without clinical lead toxicity, and from a group of control subjects not exposed to undue environmental lead. The protein was detected in all the workers, but in significantly smaller amounts in those with symptoms, and was absent from controls. The synthesis of the protein is induced at blood lead concentrations above 1.9 mumol/L, but is reduced in workers susceptible to clinical lead toxicity at blood lead concentrations below 4.0 mumol/L. The activity of the red blood cell dithiothreitol (DTT)--activated 5-aminolaevulinate dehydratase (ALA-D) was correlated with the concentration of the low-molecular-weight protein, with both being particularly low in the symptomatic workers. Previous studies have shown that the protein binds lead. By sequestrating excess lead into a non-toxic form, the protein may have a protective role in preventing clinical, and reducing biochemical, lead toxicity.
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Affiliation(s)
- Y Lolin
- Department of Chemical Pathology, Brook General Hospital, London, UK
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Fujita H, Ishihara N. Evidence of the induction of de novo synthesis of delta-aminolaevulinate dehydratase by lead. BRITISH JOURNAL OF INDUSTRIAL MEDICINE 1988; 45:710-2. [PMID: 3196665 PMCID: PMC1009682 DOI: 10.1136/oem.45.10.710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Inhibition of delta-aminolaevulinate (ALA) dehydratase (porphobilinogen synthase: EC 4.2.1.24) coupled with an increase in the enzyme concentration was observed in the liver of rats exposed to lead by mouth for 150 days. ALA dehydratase concentration increased by 25% in rats exposed to lead and cell free translation also showed an increase in de novo synthesis of ALA dehydratase by 20% in the liver of rats exposed to lead. The addition of lead in vitro to the cell free translation system had no effect on the de novo synthesis of ALA dehydratase. These results suggest that exposure to lead caused a transcription dependent induction of ALA dehydratase which might compensate for the enzyme inhibition by lead.
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Affiliation(s)
- H Fujita
- Department of Environmental Health, Tohoku University School of Medicine, Japan
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Fujita H, Koizumi A, Furusawa T, Ikeda M. Decreased erythrocyte delta-aminolevulinate dehydratase activity after styrene exposure. Biochem Pharmacol 1987; 36:711-6. [PMID: 3827952 DOI: 10.1016/0006-2952(87)90723-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
delta-Aminolevulinate dehydratase (ALA-D:porphobilinogen synthase, 5-aminolevulinate hydro-lyase, EC 4.2.1.24) activity was depressed markedly in red cells of rats exposed to 0.21 g/m3 styrene, a chemical widely used in commercial products. The depression was not restored in vitro after treatment with dithiothreitol and zinc. Consistent with this finding, radioimmunoassay of the enzyme protein demonstrated reduction in the enzyme concentration by styrene exposure. There was a good correlation between the decrease in enzyme activity and its concentration in the styrene-treated animals, suggesting that the depression of the enzyme activity was essentially due to the reduction in the enzyme content. Decrease in the enzyme content in bone marrow cells to almost the same extent as that in erythrocytes seems to indicate the decreased synthesis of ALA-D in the bone marrow. In vitro studies showed that styrene 7,8-oxide, the major intermediate of styrene metabolism, decreased the activity of purified ALA-D but that styrene, the parent compound itself, had no inhibitory effect. The activity and concentration of erythrocyte ALA-D in workers chronically exposed to styrene were also depressed significantly. These findings indicate that the styrene exposure-mediated decrease of ALA-D activity in erythrocytes was a reflection of reduction in the enzyme protein, which may have been the result of styrene 7,8-oxide action, and they suggest that a similar process may also be involved in the reduction of erythrocyte ALA-D in styrene-exposed workers.
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Hollebone BR, Johnson PM, Chakrabarti CL, Karwowska R. Evidence of differential hematopoietic compensation to lead intoxication in blood, liver and kidney. J Appl Toxicol 1986; 6:419-24. [PMID: 3805569 DOI: 10.1002/jat.2550060607] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The dependence of fluorescent porphyrin levels on the concentration of lead in blood, liver and kidney has been examined as functions of both the level and duration of dosing. Individually housed male Wistar COBS rats of 200 g were randomly selected for 3, 7, 21 and 35 day dosing periods in groups of: control, 50, 100 and 1000 ppm dosing in drinking water. The plot of all data points for porphyrin concentration against measured lead burden covers the same range of levels and closely resembles the scatter of data observed in humans. However, subsets of this plot defined by individual dose levels and durations yield well-defined linear relationships. At all dose levels at 7 days the correlation of porphyrin concentration to lead tissue burden is negative in all tissues, showing a direct inhibition of hemopoiesis with lead burden. Depending on the tissue the slope becomes less negative, or, as in blood, positive at 21 and 35 days at all doses. This compensation is most rapid in blood, then liver and is least evident in kidney. The time at which compensation is observed is the same for all doses in each tissue and seems therefore, to depend on the rate of protein turnover in different tissue types. These results suggest that a direct correlation of porphyrin concentration to lead burden is not valid without knowledge of the dosing history. As well, evidence of compensation in one tissue does not imply successful compensation in other affected tissues where regeneration rates are slower.(ABSTRACT TRUNCATED AT 250 WORDS)
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Lolin Y, O'Gorman P. delta-Aminolaevulinic acid dehydratase as an index of the presence and severity of lead poisoning in acute and chronic lead exposure. Ann Clin Biochem 1986; 23 ( Pt 5):521-8. [PMID: 3767287 DOI: 10.1177/000456328602300506] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The activity of delta-aminolaevulinic acid dehydratase (ALA-D; porphobilinogen synthase) was measured in whole blood from a group of workers with acute exposure to lead and with low blood lead levels, a group of workers with chronic lead exposure and high blood lead levels, and a group of people without undue environmental lead exposure. The activity of ALA-D was reduced significantly at low blood lead levels only if undue exposure to lead had occurred, and was thus a reflection of low level lead poisoning. In chronic lead exposure the enzyme was not invariably reactivated fully with dithiothreitol, indicating more severe enzyme poisoning. The one lead worker with symptomatic lead poisoning had the most marked enzyme suppression. Measurement of both ALA-D activity and blood lead levels was more useful than the measurement of blood lead levels alone in the diagnosis and assessment of the severity of lead poisoning.
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Fujita H, Koizumi A, Hayashi N, Ikeda M. Reduced synthesis of 5-aminolevulinate dehydratase in styrene-treated rats. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 867:89-96. [PMID: 3718991 DOI: 10.1016/0167-4781(86)90068-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
5-Aminolevulinate dehydratase (porphobilinogen synthase; 5-aminolevulinate hydro-lyase, EC 4.2.1.24) preparations purified from rat liver and erythrocytes are indistinguishable in terms of molecular weight, subunit size, immunoreactivity, amino-acid composition and kinetic properties, suggesting that the enzyme from liver and erythrocytes are identical. Intraperitoneal injection of styrene to rats decreased 5-aminolevulinate dehydratase activity in both erythrocyte (to 8% of the control) and the liver (to 40% of the control). Studies utilizing polysome-directed cell-free translation indicated that hepatic synthesis of the enzyme was inhibited by styrene at the transcriptional level. In vitro addition of styrene 7,8-oxide, a major intermediate of styrene, to purified 5-aminolevulinate dehydratase resulted in a loss of immunoassayable enzyme protein to less than 1% of the untreated control. These findings suggest that the decrease in 5-aminolevulinate dehydratase caused by in vivo treatment of styrene is partially due to a transcription-dependent decrease in the enzyme synthesis, and partially to post-translational alteration of the structure of the enzyme protein.
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