title: Influence of supplemental glutathione on selenite-mediated growth inhibition of canine mammary cells.
abstract: Present studies show the in vitro addition of glutathione (GSH) can significantly alter selenite induced growth inhibition of mammary tumor cell line 13 (CMT-13). Preincubation with 100 microM GSH for 24 h partially prevented the growth inhibition caused by 12.6 microM selenite. Pre-incubation with 100 microM GSH for 48 h completely prevented the growth inhibition caused by 12.6 microM selenite. In marked contrast, simultaneous addition of GSH and selenite dramatically increased the severity of selenite-mediated growth inhibition and resulted in cell death. Exposure to selenite (12.6 microM) increased intracellular GSH throughout the 3 day incubation period. Addition of GSH to the medium also led to an approximate 25% increase in intracellular GSH that persisted for 72 h. Cellular retention of selenium following selenite supplementation was decreased up to 70% by GSH preincubation yet increased markedly (greater than or equal to 240%) by the simultaneous addition of GSH and selenite. The rate of selenite uptake was not consistently altered by GSH pretreatment. However, the simultaneous addition of GSH and selenite resulted in a dramatically increased rate of selenium uptake. These data indicate that extracellular GSH can alter the toxicity of supplemental selenite. The protective effect of GSH pre-incubation against selenite toxicity appears to relate to altered selenium retention.
authors.affiliation: Department of Food Science, University of Illinois, Urbana 61801.
authors.forename: M J
authors.initials: MJ
authors.lastname: Kuchan
authors.forename: J A
authors.initials: JA
authors.lastname: Milner
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004285:Dogs; D004347:Drug Interactions; D005978:Glutathione / Q000494:pharmacology*; D008325:Mammary Neoplasms, Experimental / Q000378:metabolism / Q000473:pathology*; D020887:Selenious Acid; D012643:Selenium / Q000378:metabolism / Q000494:pharmacology*; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism / Q000473:pathology
chemical_list: D020887:Selenious Acid; D005978:Glutathione; D012643:Selenium