Title of article :
The Presence of Lead Decreases the Availability of wicso-2,3-Dimercaptosuccinic Acid for Analysis in the Monobromobimane Assay
Author/Authors :
Lever، Susan Z. نويسنده , , Parsons، Teresa L. نويسنده ,
Issue Information :
ماهنامه با شماره پیاپی سال 1999
Pages :
-1056
From page :
1057
To page :
0
Abstract :
meso-2,3-Dimercaptosuccmic acid is a suitable chelating agent for routine pharmacotherapy of lead poisoning in children. Administration of meso-2,3-dimcrcaptosuccimc acid presumably permits complexation of lead in vivo, allowing excretion through urine or feces. Quantification of the lead is achieved independently from the analysis of meso-2,3-dimercaptosuccinic acid and metabolites from the monobromobimane assay. To date, no direct chemical characterization of the Pb species excreted in urine has been successful. Pharmacokinetic correlation of lead excretion with excretion ofmeso-2)3-dimercaptosuccinic acid and metabolites has been utilized as an indirect method to draw conclusions regarding the identity of the active chelating agent. In this study, we hypothesized that the Pb-coordinated thiols are not reactive with respect to monobromobimane, and thus, the active chelator contained in the lead complex escapes detection. We performed variations of the assay and found that (1) the fluorescence detector response for the meso-2,3-dimercaptosuccinic acid-monobromobimane adduct was clearly attenuated as a function of added Pb, (2) when mc.-?o-2,3-dimercaptosuccimc acid and monobromobimane were mixed prior to the addition of lead, the lead had no effect on detector response, (3) the addition of dithiothreitol does not affect the ability of Pb to react with meso2,3-dimercaptosuccinic acid and verifies that oxidation of meso-DMSA had not occurred, and (4) the addition of ethylenediaminetetraacetic acid to the assay reverses the result found in point I, presumably through trans chelation of the Pb-DMSA complex. Indirect quantification of the Pb-DMSA complexes found in urine might be accomplished through modification of the standard monobromobn-nane assay for analysis of meso-2,3-dimercaptosuccinic acid.
Keywords :
Computational methods in statistical physics , Nonlinear dynamics , modeling , Theory , computer simulation
Journal title :
Chemical Research in Toxicology
Serial Year :
1999
Journal title :
Chemical Research in Toxicology
Record number :
25168
Link To Document :
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