Phosphate compounds as iron chelators in animal cell cultures.
We have studied the capacity of a number of phosphate compounds to act in the double role as a phosphate source and a detoxifier of ferric chloride hydroxo compounds, i.e. as Fe(III) chelators. The tested compounds were: orthophosphate, trimetaphosphate, alpha-glycerophosphate, beta-glycerophosphate, phytic acid, and phosphorylcholine; the test organism the ciliate protozoon Tetrahymena thermophila, an animal cell; and the nutrient medium was synthetic, consisting solely of low-molecular-weight compounds. We assessed growth rates of cells in two experimental series. First, phosphate-starved cells were exposed to the tested phosphate compound as the only phosphate source and the ferric chloride concentrations were varied stepwise from 0 to 1000 microM. Second, we offered the cells orthophosphate as a phosphate source and selected phosphate compounds as chelators. The cell growth results allow the following conclusions: orthophosphate, trimetaphosphate, alpha-glycerophosphate, and beta-glycerophosphate are excellent phosphate sources; trimetaphosphate, alpha-glycerophosphate, beta-glycerophosphate, and phytic acid are excellent Fe(III) chelators; of the tested compounds trimetaphosphate, alpha-glycerophosphate, and beta-glycerophosphate are excellent in the double role as a phosphate source and a ferric chloride hydroxo detoxifier, i.e. as a Fe(III) chelator.
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Rasmussen
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Toftlund
D000818:Animals; D002478:Cells, Cultured; D002712:Chlorides; D005290:Ferric Compounds / Q000378:metabolism / Q000494:pharmacology; D005994:Glycerophosphates / Q000494:pharmacology; D007501:Iron / Q000378:metabolism; D007502:Iron Chelating Agents; D010710:Phosphates / Q000494:pharmacology*; D010767:Phosphorylcholine / Q000494:pharmacology; D010833:Phytic Acid / Q000494:pharmacology; D011122:Polyphosphates / Q000494:pharmacology; D013768:Tetrahymena / Q000378:metabolism*
D002712:Chlorides; D005290:Ferric Compounds; D005994:Glycerophosphates; D007502:Iron Chelating Agents; D010710:Phosphates; D011122:Polyphosphates; D010767:Phosphorylcholine; D010833:Phytic Acid; C029620:alpha-glycerophosphoric acid; D007501:Iron; C009293:trimetaphosphoric acid; C024555:ferric chloride; C031463:beta-glycerophosphoric acid