Kostial K, Restek-Samarzija N, Blanusa M, Piasek M, Jones M M, Singh P K
Department of Mineral Metabolism, Institute for Medical Research and Occupational Health, Zagreb, Republic of Croatia.
Pharmacol Toxicol. 1997 Nov;81(5):242-4. doi: 10.1111/j.1600-0773.1997.tb00054.x.
Racemic dimercaptosuccinic acid (DMSA) was found more efficient than the meso-isoform in enhancing the removal of mercury in rats. However, racemic-DMSA has recently been found more toxic. The efficiency of combined oral treatment with the two isoforms of DMSA for removal of mercury has now been evaluated. Female albino rats were treated orally for four days with meso- (M) and/or racemic- (R) DMSA (1 mmol/kg each), five days after a single intraperitoneal administration of 203Hg with 0.5 mg HgCl2/kg. The animals were divided into six groups according to the number of treatments with each isomer: control (untreated), 4M, 1R + 3M, 2R + 2M, 3R + 1M, and 4R. Whole body, kidney, liver and brain mercury contents were measured nine days after 203Hg administration. In all treated groups retention in the whole body and kidneys was greatly reduced. The groups treated with racemic-DMSA, regardless of the number of doses, showed a greater removal of mercury than the group treated with meso-DMSA alone (4M). All treatments were less efficient in reducing liver retention, and the brain retention was not affected. It was concluded that even a single application of the more toxic racemic-DMSA during a four-day oral treatment regimen is sufficient to improve the removal by meso-DMSA of mercury from rats.
消旋二巯基丁二酸（DMSA）在促进大鼠体内汞的排出方面比内消旋异构体更有效。然而，最近发现消旋DMSA毒性更大。现已评估了两种DMSA异构体联合口服治疗对汞排出的效果。雌性白化大鼠在腹腔注射203Hg和0.5mg HgCl2/kg（每千克体重）后5天，分别口服中（M）和/或消旋（R）DMSA（各1mmol/kg）4天。根据每种异构体的治疗次数将动物分为六组：对照组（未治疗）、4M、1R + 3M、2R + 2M、3R + 1M和4R。在给予203Hg后9天测量全身、肾脏、肝脏和大脑中的汞含量。在所有治疗组中，全身和肾脏中的汞潴留量均大幅降低。无论剂量多少，接受消旋DMSA治疗的组比单独接受内消旋DMSA治疗的组（4M）汞排出量更大。所有治疗在降低肝脏汞潴留方面效果较差，且对大脑汞潴留无影响。得出的结论是，即使在为期4天的口服治疗方案中单次应用毒性更大的消旋DMSA，也足以提高内消旋DMSA对大鼠体内汞的排出效果。
