BACKGROUND: Metal induced toxicity with wide range of physiological, biochemical and behavioral dysfunctions was reported in many studies. The chelation has been used for treatment to toxic metalsâ exposure for many years. In our current clinical study, we compared different chelation protocols and two forms of EDTA (sodium calcium edetate and sodium edetate) in treatments of toxic metal exposure.
METHODS: A 24 h urine samples were collected from each subject before and after treatment by Ca-EDTA or Na-EDTA. The levels of toxic and essential metals were measured by Atomic Absorption Spectrometer (AAS) with graphite furnace and by Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES). The cellular levels of ATP were determined by ATP-bioluminescence assay. Mitochondrial potential was measured by fluorometer and flow-cytometer after cellsâ staining by mitochondrial dye.
RESULTS: Data from over 600 patients with a variety of complaints, but not acute toxic mineral exposure, given chelation therapy with sodium EDTA or calcium EDTA, were analyzed. Ca-EDTA and Na-EDTA at intravenous infusions of 3 g per treatment were equally effective in removing lead from the body, while Ca-EDTA was more effective in aluminum removal. The removal of lead was dose dependent but non-linear. Chelation by different doses of Na-EDTA (3 g and 1 g) resulted in mean difference in lead urine less than 50%. In addition, deficiencies in essential minerals correlated with greater pre-treatment lead and aluminum levels. The intrinsic toxicity of EDTA on cells was investigated. EDTA concentrations above 600 uM reduced cellular energy metabolism.
CONCLUSION: Based on our data, we proposed that low dosages of chelating agents might be preferential for patients with noâoccupational exposure, as the benefit of chelation is not linear with dosage, the risk of exposure to antidotes is increasing with increased dosages, and excretion of essential metals significantly increases with increased antidote dosage.
NADH, chelation, lead, essential metals