Abstract
Summary
The ability of certain tissues from anemic dogs to form copro- and protoporphyrins from glycine and acetate or from delta-aminolevulinic acid (ALA) has been compared with that of tissues from normal control dogs. None of the tissues studied formed porphyrins from glycine and acetate. However, tissues from normal dogs formed porphyrins from ALA, and in decreasing order of activity, liver, spleen, kidney, and heart. The tissues from the phenylhydrazine-treated dogs showed significantly less copro- and protoporphyrin formation than did those of the control dogs. Porphyrin synthesis in the spleen was especially decreased. In contrast, all tissues from the group made anemic by bleeding showed increased porphyrinogenesis as compared with the controls. The same results were obtained in dogs similarly treated but administered added iron. It is suggested that the decrease of porphyrin biosynthesis observed in the tissues from the phenylhy-drazine-treated dogs may result from an in vivo “feedback” inhibition by coordinate repression by heme or possibly a related metabolite. The increased porphyrinogenesis observed in the tissues of the dogs made anemic by bleeding may be related, either directly or indirectly, to erythropoietin or to some other hemopoietic factor.
Get full access to this article
View all access options for this article.