Porphyrin biosynthesis in the erythrocytes of patients with sideropenic anaemias

Abstract

SYNOPSISThe ability of erythrocytes to synthesize porphyrins from 8-aminolaevulic acid was compared in healthy people, patients with true iron-deficiency anaemia, and anaemic patients with rheumatoid arthritis. Porphyrin synthesis was found to be impaired in true iron deficiency but not in rheumatoid arthritis cases showing a similar degree ofanaemia. The 8-aminolaevulic acid dehydratase activity and the rate of porphobilinogen synthesis did not differ in the three groups studied. The most probable mechanism of impairment of porphyrin synthesis in the anaemia of true iron deficiency seems to be a partial block in the conversion of porphobilinogen into porphyrins. High endogenous and exogenous protoporphyrin concentration did not affect the synthesis of porphyrins.

Haem biosynthesis studied in patients with rheumatoid arthritis

“…Our results are different from those described by Gutniak, Kopec, and Nieczaj (1971). Their patients with rheumatoid arthritis seem to have a high degree of iron deficiency which is the most reasonable explanation of the different results.…”

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

“…There is good evidence that in iron deficiency anaemia both globin [21] and haem biosynthesis are disturbed [2,6]. Thus, various authors confirmed that in this condition the free erythrocyte protoporphyrin (EPP) is increased [8,14,16; Lyberatos et cl., unpublished data].…”

Aberration of porphyrin metabolism in iron-deficient anaemic rats (Short Communication)

“…(units/ml) (Calissano et al, 1966), mouse liver (Coleman, 1966) and Rhodopseudomonas spheroides (Nandi et al, 1968) has been observed in vitro, it is unlikely to be operative in vivo because of compartmentalization of porphyrin biosynthesis (Sano & Granick, 1961;Sardesai et al, 1965). Reports on 5-aminolaevulinate dehydratase activity in human erythrocytes are opposite and conflicting (Rubino et al, 1960;Lichtman & Feldman, 1963;Battistini et al, 1971;Gutniak et al, 1971;Mazza et al, 1971). In iron-deficient rats the enzyme activity was found to be unaltered when expressed as units/ml of blood, but showed a significant increase when expressed as units/ml of packed erythrocytes.…”