MONOISOAMYL ESTER OF DMSA REDUCES HG-203(NO3)(2) RETENTION IN RATS .1. CHELATION-THERAPY DURING PREGNANCY

In this study, efficacy of monoisoamyl meso-2,3-dimercaptosuccinate (M i-ADMS) was tested to mobilize mercury in the period of gestation in r ats. Its action was compared to meso-2,3-dimercaptosuccinic acid (DMSA ). Pregnant dams (in second third of gestation) received a single intr avenous injection of Hg-203(NO3)(2) and oral chelating therapy with DM SA or Mi-ADMS 0.5, 24, and 48 hours after that. Each chelator was admi nistered in three single doses of 0.5 mmol/kg body weight on three con secutive days. The fifth day after Hg-203 exposure, retentions were me asured in whole body, organs, and fetuses. Results (expressed as the p ercentage of Hg-203 dose) showed that all retention values among treat ed animals were lower than in the control group. Significantly higher reduction of whole body gut, Liver, kidney, and brain retentions in Mi -ADMS (to 2-5% of control values) than in DMSA-treated groups (to 37-8 0% of control values) was found. Hg-203 retention in uterus, fetuses, and placentae were reduced to 7-8% in Mi-ADMS and to 41-56% of control value in DMSA group. The major routes of Hg-203 excretion after DMSA treatment was urine, whereas fecal excretion was the same as that of c ontrols. After Mi-ADMS treatment, both urinary and fecal Hg-203 excret ions were similar to 2-3 times higher than the control values resultin g in the lowest body retention. (C) 1997 Wiley-Liss, Inc.