Toxicity to the Urothelium of Calcium Chelating Agents for Chemolysis

Abstract

Solutions, based on calcium chelating agents, with excellent prospects as litholytic agents in vitro were tested on toxicity to the mucosa of the bladder of the rat. The following compounds were tested at a concentration of 12.5 mM., buffered with triethanolamine 0.2 M at pH 8 and 8.5: ethylenediaminetetra acetic acid with as cation H2+, Li+, Na+, K+, and Cs+, trans-cyclohexane-1.2 diaminetetra acetic acid (cations H+, Na+, K+), diethylenetriamine penta acetate (cations H+, Na+, K+), disodiumethyleneglycol-bis (2 aminoethyl) tetra acetic acid and disodium hydroxyethylethylenediamine tetra acetate. All agents were found to be very noxious to the bladder mucosa of the rat and are unlikely to be safe for clinical use.

Development of an in vitro Assay for the Screening of Substances Capable of Dissolving Calcium Oxalate Crystals

“…In fact, although dissolution of CaOx in vitro has been described [7][8][9][10], a che-molytic agent for the treatment of CaOx stones is not available yet. However, since research in the field of metal chelators is very active [11], new calcium binding compounds, less toxic than the ones now available [12,13], may eventually be developed. Some of these substances could be of potential usefulness in the treatment of CaOx stones, on condition that their capability of dissolving CaOx, an extremely insoluble salt (Ksp = 2.32 !…”