title: Danazol, a new steroidal inducer of delta-aminolevulinic acid synthetase.
abstract: Danazol (a derivative of 17 alpha-ethinyl testosterone) has recently been reported to cause clinical exacerbations of acute intermittent porphyria. In the present study, we demonstrate that danazol is an inducer of hepatic delta-aminolevulinic acid synthetase and that it increases hepatocyte porphyrin production using a chick embryo model. The findings provide an explanation for the clinical observations. Although danazol is a porphyrinogenic agent in the chick embryo and humans it has been reported to be ineffective as a porphyrinogen in rats. The present findings, therefore, also confirm the superiority of the chick embryo as a model system for the screening of drugs and chemicals which may have the potential to cause clinical exacerbations of porphyria.
mesh_terms: D000624:5-Aminolevulinate Synthetase / Q000096:biosynthesis*; D000818:Animals; D002478:Cells, Cultured; D002642:Chick Embryo; D003613:Danazol / Q000494:pharmacology*; D004790:Enzyme Induction / Q000187:drug effects; D008099:Liver / Q000196:embryology / Q000201:enzymology; D011245:Pregnadienes / Q000494:pharmacology*; D011524:Protoporphyrins / Q000096:biosynthesis
chemical_list: D011245:Pregnadienes; D011524:Protoporphyrins; D000624:5-Aminolevulinate Synthetase; D003613:Danazol