Acute effects of the heavy metal antidotes DMPS and DMSA on circulation, respiration, and blood homoeostasis in dogs

Effects of Repeated Administration of Dithiol Chelating Agent - Sodium 2,3-Dimercapto-1-propanesulphonate (DMPS) - On Biochemical and Haematological Parameters in Rabbits

The effects of weekly intravenously administered a dithiol chelating agent - sodium 2,3-dimercaptopropanesulphonate (DMPS) - in a single dose of 50 mg/kg/week for 10 weeks on biochemical and haematological parameters were studied in rabbits. DMPS was well tolerated, an increase in body weight was similar in the DMPS-treated and control animals. DMPS caused significant decrease in plasma calcium and vitamin E concentrations at the end of the experiment. No significant differences in haematological parameters between the DMPS and control groups were observed. A significant decrease in magnesium content in myocardial tissue was observed in the DMPS-treated rabbits. The above-mentioned biochemical changes should be taken into account in studies of possible chelating and radical scavenging effects of DMPS in various pathological conditions.

One-, two-, and three-dimensional superstructures of gold nanorods induced by dimercaptosuccinic acid

A method is described for assembling gold nanorods into one-, two-, and three-dimensional superstructures. The addition of dimercaptosuccinic acid (DMSA) into the nanorod solution was found to induce self-assembly of the latter to one-dimensional "tapelike", two-dimensional "sheetlike" and three-dimensional "superlattice-like" structures depending on the DMSA concentration. The assembly was found to follow a smectic structure, where the nanorod long axes are parallel to each other. The rods are spaced 8.5 +/- 0.3 nm apart in the resulting structures, which extend over several micrometers in length. Organizations perpendicular to the grid were also found. The nanorod tapes were found to bend, and they form circular assemblies as well. The assembly and morphology of the nanorod structures were characterized by transmission electron microscopy and UV-vis spectroscopy. The effect of the DMSA concentration as well as the pH of the medium was also studied. On the basis of several control experiments utilizing similar molecules, charge neutralization of the nanorods by the carboxylic group of DMSA was found to be the principal reason for such an assembly, while the mercapto groups render additional stability to its structure. A mechanistic model of the assembly is proposed. This type of assembly would plausibly function as a plasmonic waveguide in potential nanodevices.

Acute arsenic poisoning treated by intravenous dimercaptosuccinic acid (DMSA) and combined extrarenal epuration techniques

Arsenic poisoning was diagnosed in a 26-year-old man who had been criminally intoxicated over the last two weeks preceding admission by the surreptitious oral administration of probably 10 g of arsenic trioxide (As2O3). The patient developed severe manifestations of toxic hepatitis and pancreatitis, and thereafter neurological disorders, respiratory distress, acute renal failure, and cardiovascular disturbances. In addition to supportive therapy, extrarenal elimination techniques and chelating agents were used. Dimercaprol (BAL) and dimercaptosuccinic acid (DMSA or succimer) were used simultaneously as arsenic chelating agents for two days, and thereafter DMSA was used alone. DMSA was administered by intravenous (20 mg/kg/d for five days, then 10 mg/kg/d for six days) and intraperitoneal route. Intravenous DMSA infusion was well tolerated and resulted in an increase in arsenic blood concentration immediately after the infusion. Continuous venovenous hemofiltration combined with hemodialysis, and peritoneal dialysis were proposed to enhance arsenic elimination. It was calculated that over an 11-day period 14.5 mg arsenic were eliminated by the urine, 26.7 mg by hemodialysis, 17.8 mg by peritoneal dialysis, and 7.8 mg by continuous venovenous hemofiltration. These amounts appeared negligible with regard to the probable ingested dose. The patient died on day 26 from the consequences of multiple organ failure, with subarachnoid hemorrhage and generalized infection caused by Aspergillus fumigatus.

Myocardial elements content and cardiac function after repeated i.v. administration of DMPS in rabbits

1. A dithiol chelating agent--2,3-dimercapto-1-propanesulphonate (DMPS)--may be administered in acute or chronic intoxication with certain heavy metals (e.g. cadmium, cobalt, lead) that may cause cardiotoxicity. 2. DMPS can act as a depleter of physiologically important elements (e.g. potassium, magnesium, calcium) in various tissues including cardiac one. The possibility of subsequent alteration in cardiac function cannot be excluded. 3. Changes in the myocardial concentration of the above mentioned elements at the end of the experiment and cardiac function were studied during repeated i.v. administration of DMPS as single doses of 50 mg/kg/ week for 10 weeks in rabbits. Biochemical, haematological and histological examinations were also performed. 4. Most of the measured parameters were not affected by the repeated administration of DMPS. A significant decrease in magnesium and a near significant decrease in calcium in cardiac muscle was not accompanied by functional or morphological changes. It is still suggested, however, that care should be taken in using DMPS for treating patients with cardiotoxicity as a result of poisoning with heavy metals.