The effect of iron substrate on mitochondrial haem synthesis in copper deficiency.

Studies of iron utilization and haem synthesis were carried out with hepatic mitochondria obtained from copper-deficient and pair-fed control rats. Ferric chloride can be used as Fe substrate for mitochondrial haem synthesis in the presence of succinate. Utilization is further enhanced by the addition of FMN. Ferritin does not support haem synthesis in the presence of succinate alone, but does support haem synthesis when FMN is added. Mitochondrial haem synthesis is impaired in Cu deficiency when either FeCl3 or homologous ferritin is used as Fe substrate. The results of the present study suggest that impaired haem synthesis in Cu deficiency occurs at a step following the chemical reduction of Fe substrate.