title: Selenium deficiency suppresses the S-glutathiolation of carbonic anhydrase III in rat hepatocytes under oxidative stress.
abstract: To examine the modification of reactive sulfhydryls of carbonic anhydrase III (CA III), hepatocytes were prepared by collagenase perfusion from Se deficient and Se-adequate male Sprague-Dawley rats. After 24 h in culture, hepatocytes were treated for 15-30 min with one of two oxidative stressors, t-butyl hydroperoxide (t-BuOOH) or menadione. Modification of CA III was measured by isoelectric focusing/immunoblotting. Formation of glutathione disulfide (GSSG) during oxidative stress was markedly less in hepatocytes of Se-deficient rats than in those of Se-adequate rats. During treatment with t-BuOOH, GSSG formation in hepatocytes from Se-adequate rats reached a maximum at 3 min, and then GSSG was gradually reduced to glutathione. After menadione treatment, intracellular GSSG irreversibly increased in hepatocytes of Se-adequate rats but not in those of Se-deficient rats. A modification of CA III that was reversible by dithiothreitol treatment concurred with the formation of GSSG during treatment with either t-BuOOH or menadione. Although modification of CA III occurred in hepatocytes from Se-deficient rats, the extent of modification was significantly less than in Se adequacy, and the modification was less reversible by dithiothreitol than in hepatocytes from Se-adequate rats. Selenium deficiency may be useful in examining the importance of modification of specific proteins subjected to oxidative stress.
authors.affiliation: Food Science and Human Nutrition, Iowa State University, Ames 50011.
authors.forename: C K
authors.initials: CK
authors.lastname: Lii
authors.forename: S
authors.initials: S
authors.lastname: Hendrich
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D015153:Blotting, Western; D002256:Carbonic Anhydrases / Q000378:metabolism*; D002478:Cells, Cultured; D005978:Glutathione / Q000031:analogs & derivatives / Q000096:biosynthesis / Q000378:metabolism*; D019803:Glutathione Disulfide; D007525:Isoelectric Focusing; D008099:Liver / Q000201:enzymology*; D008297:Male; D016877:Oxidants / Q000494:pharmacology; D010084:Oxidation-Reduction; D010545:Peroxides / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012643:Selenium / Q000172:deficiency* / Q000494:pharmacology; D013997:Time Factors; D014812:Vitamin K / Q000494:pharmacology; D020122:tert-Butylhydroperoxide
chemical_list: D016877:Oxidants; D010545:Peroxides; D014812:Vitamin K; D020122:tert-Butylhydroperoxide; D002256:Carbonic Anhydrases; D005978:Glutathione; D012643:Selenium; D019803:Glutathione Disulfide