title: Inhibitory effect of selenium on enzymes involved in heme biosynthetic pathway in chick embryos.
abstract: Effect of different concentrations of selenium (Se) on heme biosynthesis was studied at different developmental stages of chick embryo. The first rate limiting enzyme ALA-synthase (ALA-S; E.C.2.3-1.37) activity was enhanced by selenium, while hepatic and blood ALA-dehydratase activity (ALA-d; E.C.3.2.1.24) was decreased. Hepatic and blood free-sulfhydryl (-SH) group contents were significantly decreased by Se. Further, hepatic aminolevulinic acid (ALA) and total blood porphyrin levels were enhanced and hepatic heme levels were depleted by selenium exposure. Heme biosynthesis was maximally inhibited in the E4 (4th day injected embryos) when compared to later periods.
authors.affiliation: Department of Zoology, Sri Venkateswara University, Tirupati, A.P., India.
authors.forename: K
authors.initials: K
authors.lastname: Padmaja
authors.forename: R
authors.initials: R
authors.lastname: Ramamurthi
authors.forename: A R
authors.initials: AR
authors.lastname: Prasad
mesh_terms: D000624:5-Aminolevulinate Synthetase / Q000378:metabolism*; D000622:Aminolevulinic Acid / Q000097:blood / Q000378:metabolism; D000818:Animals; D002642:Chick Embryo; D003609:Dactinomycin / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006418:Heme / Q000096:biosynthesis*; D008099:Liver / Q000187:drug effects / Q000196:embryology / Q000201:enzymology / Q000378:metabolism; D000623:Porphobilinogen Synthase / Q000037:antagonists & inhibitors*; D011166:Porphyrins / Q000097:blood / Q000378:metabolism; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012643:Selenium / Q000494:pharmacology*; D013438:Sulfhydryl Compounds / Q000032:analysis / Q000097:blood / Q000378:metabolism; D013997:Time Factors
chemical_list: D004791:Enzyme Inhibitors; D011166:Porphyrins; D011500:Protein Synthesis Inhibitors; D013438:Sulfhydryl Compounds; D003609:Dactinomycin; D006418:Heme; D000622:Aminolevulinic Acid; D000624:5-Aminolevulinate Synthetase; D000623:Porphobilinogen Synthase; D012643:Selenium