重金属暴露与生殖毒性的相关研究进展

Heavy metal exposure and reproductive toxicity:Advances in studies

重金属是影响环境的最主要的污染物之一。该类金属元素的密度高于水,广泛存在于自然环境中。微量元素如锌、铜、镍和铬,在正常水平下介导重要的生理功能和代谢调节,其摄入不足将导致相关疾病。镉、铅和汞等重金属不参与人体正常代谢,即使在体内剂量极低,也会对人体产生损害。重金属污染主要来源于工业废水、化石燃料燃烧、废水、冶炼、采矿、汽车尾气、有害垃圾倾倒和化肥滥用。重金属不能被生物降解,因此在自然界中具有较长的生物半衰期,进而导致生物富集、放大。食用受污染的蔬菜是接触重金属的途径之一。重金属能够穿过胎盘屏障,因此,这些重金属不但会对人体生殖系统产生不利影响,还会对胎儿产生影响。重金属还会对下丘脑-垂体-性腺轴产生负面影响,从而影响性成熟和生殖功能。目前环境中的重金属水平急剧上升,对重金属的生殖毒性及其拮抗药物的研究具有重要临床意义。

Heavy metals are among the major pollutants affecting the environment,with a higher density of metal element than that of water and an extensive presence in the natural environment.Trace elements such as zinc,copper,nickel and chromium mediate important physiological functions and metabolic regulation at normal levels,and insufficient intake of them will lead to related diseases.Heavy metals such as cadmium,lead and mercury do not participate in the normal metabolism of the human body and will cause damage to the body even at an extremely low dose.Heavy metal pollution mainly comes from industrial wastewater,fossil fuel combustion,wastewater,smelting,mining,vehicle exhaust,hazardous waste dumping,and fertilizer abuse.Unable to be biodegraded,heavy metals have a long biological half-life in nature,which in turn leads to bio-accumulation and-amplification.Eating contaminated vegetables is one way of being exposed to heavy metals.Heavy metals produce adverse effects not only on the human reproductive system,but also on the fetus by penetrating the placental barrier,and on the hypothalamic-pituitary-gonadal axis as well,consequently affecting sexual maturation and reproductive function.With the sharp increase of heavy metals in the environment,researches on their reproductive toxicity and antagonistic drugs have an important clinical significance.