the reduced form of a porphyrin. The porphyrinogens are the functional intermediates in the biosynthesis of heme and if oxidized to their corresponding porphyrins, such as occurs in porphyrias, are irreversibly removed from the biosynthetic pathway and accumulate in tissues. Their nomenclature corresponds to that of the porphyrins.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.