title: Expressions of N-methyl-D-aspartate receptors NR2A and NR2B subunit proteins in normal and sulfite-oxidase deficient rat's hippocampus: effect of exogenous sulfite ingestion.
abstract: Sulfites whether ingested or produced through the sulfur-containing amino acids metabolism of the animal are very active molecules and can cause cellular toxicity. Sulfite oxidase (SOX), a heme- and molybdenum containing mitochondrial enzyme, prevents mammalian cells from adverse effects of sulfite toxicity by metabolizing sulfite to sulfate. The present study was aimed to investigate effect of sulfite on the N-methyl-D-aspartate (NMDA) receptor (NMDAR) NR2A and NR2B subunits in hippocampus of normal and SOX-deficient rats. Rats were divided into four groups; (1) control group, which was given rat chow and tap water ad libitum (C), (2) sulfite group, treated with sulfite (25 mg/kg) in drinking water and commercial rat chow ad libitum (S), (3) SOX-deficient group, maintained on high-W/Mo-deficient regimen to produce SOX deficiency (D), and (4) SOX-deficient + sulfite group (DS), prepared as those in the third group and were afterwards given sulfite (25 mg/kg) additionally. Whole treatment schedule were continued for 6 weeks. Sulfite treatment caused a decrease of NR2A and NR2B subunits of the NMDAR in hippocampus of rats in S and DS groups. Interestingly, similar decrement was observed in D group, probably due to increased endogenous sulfite production. In summary, the results indicated that feeding sulfite to the rats may cause down-regulation of NMDARs by degrading NR2A and NR2B subunits of it, which may be considered as a neuro-compensatory mechanism.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Akdeniz University, 07070 Antalya, Turkey.
authors.forename: Oktay Hasan
authors.initials: OH
authors.lastname: Oztürk
authors.forename: Vural
authors.initials: V
authors.lastname: Küçükatay
authors.forename: Zafer
authors.initials: Z
authors.lastname: Yönden
authors.forename: Aysel
authors.initials: A
authors.lastname: Ağar
authors.forename: Hüseyin
authors.initials: H
authors.lastname: Bağci
authors.forename: Namik
authors.initials: N
authors.lastname: Delibaş
mesh_terms: D000818:Animals; D003071:Cognition / Q000187:drug effects; D015536:Down-Regulation; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D008297:Male; D021122:Protein Subunits / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects* / Q000378:metabolism; D050876:Sulfite Oxidase / Q000172:deficiency*; D013447:Sulfites / Q000633:toxicity*; D013997:Time Factors
chemical_list: C120997:NR2A NMDA receptor; C121001:NR2B NMDA receptor; D021122:Protein Subunits; D016194:Receptors, N-Methyl-D-Aspartate; D013447:Sulfites; D050876:Sulfite Oxidase; C025026:sodium sulfite