T HE INSERTION OF IRON into protoporphyrin is the final step of a series of reactions in the biosynthesis of heme.’ Several previous investigations have demonstrated that this step is enzyme-dependent and the enzyme has been named Theme synthetase” or “iron chelatase.” The enzyme has been extensively characterized in rat liver mitochondria,2 and Porra and Jones suggested that two enzymes may be...

Malnutrition is observed frequently in patients with pulmonary tuberculosis (TB), but their nutritional status, especially of micronutrients, is still poorly documented. The objective of this study was to investigate the nutritional status of patients with active TB compared with that of healthy controls in Jakarta, Indonesia. In a case-control study, 41 out-patients aged 15-55 y with untreated...

The activities of three erythrocyte (rbc) enzymes, arginase, pyrimidine 5'-nucleotidase (P5N), and deoxypyrimidine 5'-nucleotidase (dP5N), were compared in 16 lead workers and 14 age matched controls as correlates of blood lead (PbB) and unextracted zinc protoporphyrin (EP) concentrations. Subjects with PbB of 0.9-2.5 microM (19-52 micrograms/dl) had 6.5 +/- 0.6 IU of P5N activity with uridine ...

Erythrocyte protoporphyrin (EP) has been used for more than 30 years as an indicator of lead intoxication, iron deficiency, and porphyrias. Recently, numerous analytical problems associated with various EP methods have been reported, including a lack of consensus among investigators regarding the best calibration material or analytical procedure. We investigated commercially available protoporp...

1. Labelled glycine and/or 6-aminolaevulinic acid (ALA) were administered to a child with congenital erythropoietic porphyria (Giinther’s disease), to three normal children and to three patients with erythropoietic protoporphyria. 2. The utilization of [I5N]ALA for the synthesis of faecal ‘urobilin’ in the congenital erythropoietic patient was normal. 3. This suggests there is no significant in...

Variegate porphyria (VP) is characterized by photocutaneous lesions and acute neuropsychiatric attacks. Decreased protoporphyrinogen oxidase activity results in accumulation of protoporphyrin (ogen) IX and coproporphyrin (ogen) III. During acute attacks delta-aminolevulinic acid and porphobilinogen also increase, suggesting that porphobilinogen deaminase (PBG-D) may be rate limiting. We have ex...

BACKGROUND Iron-deficient erythropoiesis results in excess formation of zinc protoporphyrin (ZPP), which can be measured instantly and at low assay cost using portable haematofluorometers. ZPP is used as a screening marker of iron deficiency in individual pregnant women and children, but also to assess population iron status in combination with haemoglobin concentration. We examined association...

It is well know that exposure to lead causes disorders of porphyrin metabolism such as elevation of ƒÂ-aminolevulinic acid (ALA) and coproporphyrin (CP) in urine, accumulation of protoporphyrin (PROTO) in erythrocytes, and inhibition of erythrocyte ƒÂ-aminolevulinic acid dehydratase (ALAD) activity.') In addition, it has been reported that inorganic tin (II) also inhibits erythrocyte ALAD activ...