Generation of active oxygen species during coupled autoxidation of oxyhemoglobin and delta-aminolevulinic acid.

The conversion of oxyhemoglobin to methemoglobin has been shown via spectrophotometric, circular dichroism and polarographic studies to be accelerated by delta-aminolevulinic acid, a major heme-precursor accumulated in a number of heme-linked pathologies. Concomitantly, delta-aminolevulinic acid undergoes aerobic oxidation. The intermediacy of oxygen radicals in these processes was evidenced by the inhibitory effect of catalase, superoxide dismutase and mannitol. These results are relevant to the exacerbated production of active oxygen species in intermittent acute porphyria and saturnism carriers.