Study Of The Effect Of Pentetate Zinc Trisodium On The Promotion Of Lead Excretion

Lead, a non-essential trace metal is known as a toxic environmental pollutant which can threat the healthy development of many species. Lead poisoning remains a significant public health problem. Lead may induce a wide range of physiological, biochemical and behavioral dysfunctions in experimental animals and humans, including those in central nervous system, hemopoictic system, immunologic system, cardiovascular system, liver, kidney, brain and reproductive systems. Liver, kidney and brain have been considered as the target organs for the toxic effect of lead. Zn-DTPA is one of chelates. The zinc ion in Zn-DTPA can be replaced by radionuclides and heavy metals which have a higher chelating ability. Through this process, stable and hydrosoluble chelating agents are formed which can be excreted by urine. The aim of present work is to study the effect of Zn-DTPA on lead excretion by detecting the lead content in blood, liver, kidney, brain, femur and urine. The main results are as follows:1. Study of the effect of pentetate zinc trisodium on lead excretionTo acute lead poisoning mice, after injecting Zn-DTPA, lead concentration in urine is very significantly higher than that of lead control group (P<0.01). With the time going, the lead concentration in urine became less. Most part of lead excreted is within three days after first drug injection. To chronic lead poisoning mice, lead content of blood, brain and femur can be lowered significantly by Zn-DTPA with lead content of urine being significantly increased. Zn-DTPA does no significant effect on lead content of liver and kidney.2. Study of the effect of pentetate zinc trisodium by three administration route on lead excretionWe evaluate the effect of Zn-DTPA through three administration routes: intramuscular injection, intraperitoneal injection and intravenous injection and found that there was no significant difference between these three administration routes in terms of lead content in blood, liver and femur.3. Study of the effect of pentetate zinc trisodium at different sustained times on lead excretionDuring 14 days of administration, the blood lead level become less. So was the lead content of liver. There was an accumulation of lead content in femur of model group, it shows the femur was the final part of lead accumulation. Blood and femur lead level of experimental group were lowered than those of model group because of the promotion of lead excretion by Zn-DTPA.4. Study of the effect of petetate zinc trisodium on thallium excretion in acute thallium poisoning miceCompared with model group, Zn-DTPA can very significantly increase thallium content in urine and feces, especially thallium content in urine (P<0.01). The death time of mice is also delayed by Zn-DTPA.5. Study of pentetate zinc trisodium on haemolysis, cell agglutination and vascular irritationThere was no haemolysis or blood cell agglutination 30min, 1h, 2h, 3h and 4h after adding Zn-DTPA. It also possesses no vascular irritation and injury effect on rabbit vascular endothelial cell.We conclude that the lead in blood finally accumulate in the bone. The intravenous injection of the drug was safe and the promotion effect by intramuscular injection was not less than that by intravenous injection. Zn-DTPA can lower the lead content in brain and femur by the promotion of lead excretion of urine. It also has an effect on thallium excretion.