Porphyrin metabolism in children with G6PD-deficiency anemia: a model for chronic mild hemolysis

ABSTRACT

Significant abnormalities were found in children with G6PD deficiency haemolytic anaemia [n=12] compared to a group of normal children [n=25] in the same age range. These abnormalities are represented by highly significant inhibition of blood delta-aminolevulinic acid dehydratase [ALAD] activity, high blood porphyrins [coproporphyrin, CP and protoporphyrin, PP] and excessive excretion of urine porphyrins [CP and uroporphyrin, UP]. Experimental mild haemolytic anaemia was induced in guinea pigs by subcutaneous injection of aqueous solution of acetyl phenyl hydrazine. Porphyrins produced from the incubation of blood of these animals with delta-aminolevulinic acid [ALA] were analysed by thin layer chromatography [TLC] and high performance liquid chromatography [HP LC] and most of blood enzymes participating in haem biosynthesis were assayed. ALA-synthetase, uroporphyrinogen-I-synthetase and porphobilinogenase activities were all significantly higher than the corresponding values in a control group. However, uroporphyrinogen decarboxylase [UR OD] activity was significantly inhibited in acetyl phenyl hydrazine-injected animals. The incubation experiments confirmed this inhibition in UROD activity