The effects of succimer on the absorption of lead in adults determined by using the stable isotope [sup 204]Pb

• Published in: Environmental research Vol. 67:1
• Main Authors: Smith, D.R., Markowitz, M.E., Rosen, J.F., Crick, J., Flegal, A.R.
• Format: Journal Article
• Language: English
• Published: United States 01.10.1994
• Subjects: 550501 > Metabolism > Tracer Techniques; 550600 > Medicine; ABSORPTION; AGE GROUPS; ALPHA DECAY RADIOISOTOPES; BASIC BIOLOGICAL SCIENCES; CHELATING AGENTS; CHILDREN; ELEMENTS; EVEN-EVEN NUCLEI; HEAVY NUCLEI; HOURS LIVING RADIOISOTOPES; INTESTINAL ABSORPTION; ISOMERIC TRANSITION ISOTOPES; ISOTOPE APPLICATIONS; ISOTOPES; LEAD; LEAD 204; LEAD ISOTOPES; METALS; NUCLEI; RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT; RADIOISOTOPES; RADIOLOGY AND NUCLEAR MEDICINE; RETENTION; SORPTION; THERAPEUTIC USES; TRACER TECHNIQUES; UPTAKE; USES; YEARS LIVING RADIOISOTOPES 560300 > Chemicals Metabolism & Toxicology
• ISSN: 0013-9351; 1096-0953
• DOI: 10.1006/enrs.1994.1063

The chelating agent succimer (meso-2,3-dimercaptosuccine acid) is orally effective at inducing a urinary lead diuresis and a decrease in blood lead levels in lead poisoned children and adults. However, there are concerns that succimer may increase the absorption of lead from the gastrointestinal (GI) tract during treatment, particularly in cases of continuing lead exposure, which would compromise its effectiveness in reducing whole body lead stores. This preliminary study investigated the effects of succimer on the absorption of lead in adults using a stable lead isotopic tracer ([sup 204]Pb). Twelve male subjects were divided into control (no succimer), 10, and 30 mg succimer/kg body wt treatment groups of 4 individuals each. All subjects ingested a single tracer dose (200 [mu]g) of [sup 204]Pb, followed by a single oral dose of placebo (control) or succimer. Whole blood was collected at intervals of 0, 2, 4, and [approx] 26 hr following ingestion of the [sup 204]Pb tracer, and composite urine and feces samples were collected over the duration of the study ([approx] 26 hr). Mean intestinal excretion of [sup 204]Pb was reduced in the succimer-treated groups compared to the control (placebo), whereas urinary diuresis of [sup 204]Pb was higher in the succimer groups. The amount of lead [sup 204]Pb tracer accounted for at the end of the study was lower in the succimer-treated groups. These results suggest that GI lead absorption was enhanced by succimer and that succimer mediated the redistribution of lead from the circulation to other tissues. However, none of the differences between treatment groups were statistically significant (P < 0.05, t test) because of the relatively large within-group variability. This study demonstrates the utility of microgram doses of a stable lead isotopic tracer to assess the efficacy of clinical chelating agents in humans. 39 refs., 1 fig., 2 tabs.