低剂量兴奋效应作用机制的研究进展

Research Status of the Mechanism of Hormesis

近年来,毒物的低剂量兴奋效应在毒理学界倍受人们关注。它是指接触某一化学物低浓度时产生对机体有利效应,而在高浓度时却产生不良效应的现象。通过对多种毒物低剂量兴奋效应现象的研究,也已规范提出了两种主要的剂量-反应关系模型U型和β型。虽然毒物低剂量兴奋效应被证明广泛存在于不同种属、不同结构的化学物以及各种生命终点,但其具体的作用机制仍不清楚。本文综述了该现象的几种可能机制过度补偿、DNA损伤修复、自由基清除、免疫功能增强以及基因表达与调控作用。随着低剂量兴奋效应作用机制的日渐明朗,这一概念将会在毒理学界产生十分重要的影响。

In recent years, the term ＂hormesis＂ has attracted people＇s attention globally in toxicology. It was defined as the production of beneficial effects in a population at low exposures and adverse effects at high exposures to a given chemical material. By studying on the phenomenon caused by variety of toxicants, two main dose-response relationship model has been discovered： U-shaped and [3-shaped. Although hormesis has been found widely in different chemical materials and end-point of life, the specific mechanism is not clear. This paper reviews several possible mechanisms of the phenomenon： overcompensation, DNA damage repairing, free radical scavenging, immune function enhancing and gene expression and regulation. While the mechanism of hormesis becoming more and more clear, the concept will play an important role in toxicology.