In vivo and in vitro influence of selenium on DNA/RNA synthesis in spleen and lymphocytes in culture--possible mediation of changes in GSH/GSSG ratio.
Effect of superanutritional levels of selenium (Se) as sodium selenite (0.5 and 1.5 ppm) given orally to Balb/c mice for one and two weeks was observed on the rate of DNA/RNA synthesis, levels of reduced as well as oxidized glutathione (GSH and GSSG) and glutathione peroxidase (GSH-Px)/glutathione-S-transferase (GSH-S-transferase) activities in spleen. Similar effect of three different concentrations of Se (10(-7), 10(-5) and 10(-3) M) in culture media was also observed on the rate of DNA/RNA synthesis in proliferating lymphocytes taken from mice spleen. The results of the present study indicated that with increasing concentration and duration of Se treatment in vivo and in vitro, a marked inhibition of the rate of DNA/RNA synthesis was observed. Levels of total glutathione and GSSG in spleen were elevated significantly only after two weeks in 1.5 ppm treatments. Glutathione peroxidase activities in spleen decreased (p < 0.05) in 1.5 ppm group at one week and in 0.5 ppm group at two week treatment. At higher Se treatment, the activity recovered towards control. However, GSH-S-transferase in spleen remained unchanged at all treatment intervals. The results indicated that changes in glutathione system by increasing Se concentration might account for inhibition of rate of DNA/RNA synthesis.
Bansal
M P
MP
Department of Biophysics, Panjab University, Chandigarh 160014, India.
Sood
S
S
D000818:Animals; D004261:DNA Replication / Q000187:drug effects*; D005260:Female; D005978:Glutathione / Q000378:metabolism*; D019803:Glutathione Disulfide / Q000378:metabolism*; D005979:Glutathione Peroxidase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D066298:In Vitro Techniques; D008214:Lymphocytes / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D012313:RNA / Q000096:biosynthesis*; D012643:Selenium / Q000494:pharmacology*; D013154:Spleen / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism
D012313:RNA; D005979:Glutathione Peroxidase; D005982:Glutathione Transferase; D005978:Glutathione; D012643:Selenium; D019803:Glutathione Disulfide