Effect of Chelating Agents on Uptake of Ca45 and Sr85 by Defatted Bone in vitro.

Abstract

Chelating agents in buffered solutions affected the relative uptake of Ca45 and Sr85 by bone powder. Strong chelating agents, like ethylenediaminetetraacetic acid and cyclohexanediamine -tetraacetic acid, decreased the ratio of Ca45/Sr85 uptake considerably. Citrate and ATP had similar but weaker effects. No effect was shown by glucose, lactate, gluconate, bicarbonate, bicarbonate plus phosphate, glutamate, aspartate, borate, glycerophosphate, lysine, or glutathione. Strong chelating agents also decreased the relative amount of Sr85 re-_ moved by exchange. Results indicate that natural chelating agents may be partly responsible for the low Ca45/Sr85 uptake ratio by bone from serum compared with uptake from synthetic organic solutions, and emphasize the difficulty of removing Sr85 from bone with chelating agents now available.