Study On The Effect And Mechanism Of Lead And Zinc On Bone Formation In Lead And Zinc Mining

Objective:Although the events of childhood lead poisoning have occurred throughout the world. In China, children lead poisoning also shows ascendant trend. The pollution of heavy metals in lead-zinc mine is complex, which is bigger to child health,which is different from other than non-mining area environment. This research mainly include three parts; Lead and zinc exposure on the determination of lead and the children send health effects analysis in lead-zinc mine; The infected joint influence the bone metabolism of rats growing; Lead and zinc influence the proliferation and differentiation and apoptosis of milk rats.This subject study which the pollution in lead-zinc mine effects child health, especially the influence of skeleton development and body element level,and discuss preliminary on the influence mechanism of skeleton development, and provide scientific theory basis for children lead poisoning prevention in lead-zinc mine, raise the improving children's health countermeasures from the intervention of nutrition.Methods:①Population survey:select 186 children during growth and development stages in a lead-zinc smelter area as study group, select the mine 40km from the outside as a control group of 156 children, to children physical examination in the general situation(including:calcium deficiency, alopecia, anemia, easily cold), mineral elements in hair of children.②Animal experiments:select 36 weaned, wistar rats, males and females in half, body weight (46-72) g, to lead acetate (1.3mg/kg.bw), zinc sulfate (150.4mg/kg.bw), cadmium chloride (4.4 mg/kg.bw), administered by 1ml/100g.bw exposure, at the same time ferrous sulfate (119.1mg/kg.bw), calcium acetate (474mg/kg.bw), vitamin C (450mg/kg.bw), vitamin B2 (14mg/kg.bw) mixture after preparation of nutrition intervention, according to 1ml/100g.bw gavage. Rats were sacrificed three days before the metabolic experiments were killed by cervical dislocation to collect the femur bone measured lead, cadmium, calcium, iron, copper and zinc content.③Cell experiment:choose skull rats living the clean class after 3d (male and female unlimited) as cell sources,0.25% trypsin digestion, after 25min, getⅡby 0.01%, shear ground type collagenase digestion 2h obtain osteoblast (OB), use, alkaline phosphatase, alkaline phosphatase (ALP) dyeing kit and alizarin red vital staining calcified nodule identification, observe its form, and growth change, built successful SD rats OB sign in vitro system. According to the different culture solution medium added zinc and lead concentration, is divided into 10 group, the control group, the lead group (1μmol/L,10μmol/L, 100μmol/L), zinc+lead group (first give 50μmol/L,100μmol/L zinc, after intervention lead). Observe morphology, ALP OB sign groups proliferation capacity, ALP activity, caspase-3 mRNA expressions, mRNA expression changes.The study observe morphology, proliferation capacity, ALP activity, caspase-3 mRNA expressions, ALP mRNA expression.Results:①Population survey:children in the observation group about the perceived status of four the positive rate was higher (P<0.05, P<0.01). Higher Pb, Zn, Ca levels in hair of children, and statistically significant (P<0.01).The statistical analysis shows that children's hair Lead level is negative correlation with mineral elements in hair of children.②Animal experiments:Exposure in the exposed rats have increased body weight after one week, slow their growth was significantly lower than the control group (P<0.05); exposure group, body weight gain in the intervention group were lower than the control group, the difference was significant (P<0.05); rat bone lead, zinc, cadmium content in the high exposure group in the control group, the difference was statistically significant (P<0.05, P<0.01). The length and diameter of femur was smallest with the high exposure group and lead treatment second was lead treatment, and the control group and intervention group was smaller than the control group. Compared with the control group, rats exposed to calcium retention rate of stock reduction, and lead retention rate increased, the differences were statistically significant (P<0.05, P<0.01); exposed group and the intervention group were in the femur Rate of calcium retention, lead retention rate, the difference was not statistically significant (P> 0.05).③Cell experiment:Lead changed the shape of osteoblasts and the formation of markers, showing the morphological changes, decreased proliferation and ALP activity. Amount of zinc can antagonistic the effects of these features, high zinc in the morphology and proliferation capacity did not show antagonistic the effects of lead, but the high zinc combined high lead reduced the toxicity on ALP activity; Lead inhibited the expression of ALP and promoted the expression of caspase3. The amount of zinc can inhibit the expression of caspase-3 caused by lead.Conclusion:The environmental pollution had adverse effects on children's health and skeleton development in lead-zinc mine; The rat poison caused lead and zinc cadmium performed firstly weight change. Lead and zinc cadmium infected can change the morphological of femur bone, the increase of lead and cadmium on bone, iron and zinc and calcium level changed. The comprehensive nutrition intervention had certain effect on antagonist the heavy metal element. Lead can cause the morphological changes of 013, inhibit the proliferation and differentiation, zinc can antagonist to the damage effect. Lead can inhibit the expression of ALP gene on osteoblast, promote the expression of caspase3 gene. The supplement of zinc can antagonist that lead cause the expression of ALP gene cutting and caspase3 gene rising.