In Vitro Pyrrole and Porphyrin Synthesis in Lead Poisoning and Iron Deficiency*

Lichtman, Herbert C.; Feldman, Felix

doi:10.1172/jci104775

Cited by 116 publications

(32 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[14,[16][17][18] Though the mechanisms involved are not completely elucidated, elevated blood lead levels are associated with impaired haem synthesis [43][44][45] this is unlikely to be the explanation in this study as erythrocyte protoporphyrin activity was similar between Pb workers and controls. Additionally, we previously reported in our observations on the haemopoietic system in this cohort [42] that the haembiosynthetic pathway was uninhibited.…”

Section: Discussionmentioning

confidence: 63%

Decreased total and ionized calcium levels and haematological indices in occupational lead exposure as evidence of the endocrine disruptive effect of lead

Anetor

Akingbola

Adeniyi

et al. 2005

Indian J Occup Environ Med

View full text Add to dashboard Cite

The multisystem and prime environmental and occupational toxin, lead (Pb) is seldom included in the list of endocrine disruptors group like bisphenols A, B and F, nonylphenol, benzoquine, equiline etc. One hundred and thirty-seven subjects consisting of 86 lead workers and 51 unexposed individuals (as controls) participated in the study. Dietary intake including dairy products and micronutrients as assessed by 24-hour dietary recall was similar between lead workers and controls. Calcium homeostasis and haematological indices were evaluated in all subjects. Blood lead level was significantly higher in the lead workers than in controls (P<0.001). Total and ionized calcium levels were in contrast significantly decreased in lead workers compared with controls (P<0.01, P<0.001 respectively). Inorganic phosphate level though slightly raised compared to controls did not reach statistical significance (P>0.05). The haematological indices, haemoglobin, haematocrit, and mean cell haemoglobin concentration like calcium levels were all significantly reduced (P<0.001) in all cases. Semi-quantitative assessment of erythrocyte protoporphyrin was trace (±) in both lead workers and controls (i.e. similar). Serum copper level was significantly higher in Pb workers than in controls (P<0.005). These decreases are consistent with a repression of the endocrine systems regulating both erythropoiesis and calcium homeostasis resident in the proximal convoluted tubule(PCT) of the kidney; the most vulnerable site to Pb damage. Our findings therefore, appear to provide evidence or a reminder that Pb satifies the conditions defining EDCs and should be recognized as one, especially in developing countries where high environmental Pb and malnutrition co-exist and may magnify this effect.

show abstract

Section: Discussionmentioning

confidence: 63%

Decreased total and ionized calcium levels and haematological indices in occupational lead exposure as evidence of the endocrine disruptive effect of lead

Anetor

Akingbola

Adeniyi

et al. 2005

Indian J Occup Environ Med

View full text Add to dashboard Cite

show abstract

“…Thus, Heilmeyer [7] in 13 cases and Kaneko [9] in 22 cases found increased erythrocyte ¿-ALAD activ ity. On the contrary, Lichtman and Feldman [10] and Battistini et al [1] both in 9 cases had not found significant differences in comparison to normal controls. Furthermore, Sharma [19] noticed that the enzyme ac tivity in iron deficient rats was increased when expressed as units/ml packed red cells, whereas it remained unchanged when expressed as un its/ml of blood.…”

Section: Discussionmentioning

confidence: 87%

Erythrocyte <i>δ</i>-Aminolaevulinic Acid Dehydratase, Urinary Porphyrins and Porphyrin Precursors in Iron Deficiency Anaemia

Chalevelakis¹,

Lyberatos²,

Manopoulos³

et al. 1977

Acta Haematol

View full text Add to dashboard Cite

In 20 iron deficient patients and 21 normal controls the activity of the enzyme δ-ALA dehydratase of erythrocytes was assayed. In addition the urine porphyrins and porphyrin precursor excretions were measured. It was found that in sideropenic patients the erythrocyte δ-ALA dehydratase activity was almost constantly higher than in normals; the difference of the mean values being statistically significant (p < 0.005). A significant diminution of δ-ALA (p < 0.0025) urine excretion was observed, whereas the urine excretion of PBG, CP and UP was found within the normal limits. The results are compared to those reported by other authors.

show abstract

“…It is asAimed that the lead ions replace zinc in tbe molecule, resülting in loss of enzymatic activity by formatiön of lead inei> captide (4). Sulfhydryl reageiits such äs glütathione, cysteine and dithiöthreitol äs well äs zinc and manganese ions (5) restore the activity of the enzyme in vitro (2,6,7). The enzyme is inhibited by succinylacetone, a compound which accumülates in heredl·-tary tyrosinaemia (8 …”

Section: Introductionmentioning

confidence: 99%

Aminolaevulinate Dehydratase Porphyria in Infancy. A Clinical and Biochemical Study

Thunell¹,

Holmberg²,

Lundgren³

1987

Clinical Chemistry and Laboratory Medicine

View full text Add to dashboard Cite

Summary: Homozygous deficiency of aminolaevulinate dehydratase (porphobilinogen synthase, EC 4.2.1.24) was diagnosed in a small child. The clinical presentation was unique since severe Symptoms were already present in the neonatal period. The patient, a boy, now three-years old, had recurrent attacks of pain, vomiting, hyponatraemia and Symptoms of polyneuropathy engaging motor functions including respiration. The clinical course of the disease from birth on is related, äs are the results of various attempts at therapy. The patient excreted large amounts of 5-aminolaevulinic acid and coproporphyrin and minor amounts of porphobilinogen in the urine. Faecal excretion of coproporphyrin and harderoporphyrin was increased äs was erythrocyte porphyrin concentration. Diagnosis was established by the finding that erythrocyte aminolaevulinate dehydratase activity was less than 5 per cent of normal in the patient and between 26 and 51 per cent of normal in both the parents, the grandfathers and a sibling. The activity of the enzyme could not be restored by the addition of dithiothreitol (10~3 mol/1) alone, or in combination with zinc or manganese in varying concentrations. The enzyme K m did not differ between affected and nonaffected members of the family.

show abstract

In Vitro Pyrrole and Porphyrin Synthesis in Lead Poisoning and Iron Deficiency*

Cited by 116 publications

References 29 publications

Decreased total and ionized calcium levels and haematological indices in occupational lead exposure as evidence of the endocrine disruptive effect of lead

Decreased total and ionized calcium levels and haematological indices in occupational lead exposure as evidence of the endocrine disruptive effect of lead

Erythrocyte <i>δ</i>-Aminolaevulinic Acid Dehydratase, Urinary Porphyrins and Porphyrin Precursors in Iron Deficiency Anaemia

Aminolaevulinate Dehydratase Porphyria in Infancy. A Clinical and Biochemical Study

Contact Info

Product

Resources

About