摘要：Recent studies have elucidated that a variety of metals, including heavy toxic metals as well as essential metals, regulate cellular content of heme by controlling the activities of enzymes in heme metabolic pathways. This review shows that at the first and rate-limiting stages δ-aminolevulinic acid synthetase, δ-aminolevulinic acid dehydratase at the second stage and ferrochelatase, the last enzymes in the heme biosynthetic pathway, as well as heme oxygenase, the first and rate-limiting enzyme of the heme degradation, readily respond to metals (As, Cd, Cr, Co, Au, In, Fe, Pb, Mn, Hg, Ni, Pt, Se, Ag, Sn and Zn). The consequences of the metal actions on heme synthesis and degradation arise substantial depletion of cellular content of hemoprotein, cytochrome P-450. Concomitantly, this depletion alters the activity of cytochrome P-450-dependent mixed-function oxidase. Furthermore, the effects of metals on the induction of metallothionein and on the content of glutathione are also discussed.
关键词：toxic and essential metals;δ-aminolevulinic acid synthetase;δ-aminolevulinic acid dehydratase;ferrochelatase;heme oxygenase;cytochrome P-450;drug-metabolizing enzymes;metallothionein;glutathione;heme biosynthesis and degradation
