Shaner Dale L
USDA-ARS Water Management Unit, AERC Colorado State University, Fort Collins, CO 80523, USA.
Pest Manag Sci. 2004 Jan;60(1):17-24. doi: 10.1002/ps.782.
Most modern herbicides have low mammalian toxicity. One of the reasons for this safety is that the target site for the herbicides is not often present in mammals. There are approximately 20 mechanisms of action that have been elucidated for herbicides. Of these, some do share common target sites with mammals. The mechanisms include formation of free radicals, protoporphyrinogen oxidase (PROTOX), glutamine synthetase (GS) and 4-hydroxyphenylpyruvate dioxygenase (HPPD). PROTOX, HPPD and GS inhibitors have been shown to inhibit these enzymes in both plants and mammals and there are measurable effects in mammalian systems. However, the consequences of inhibiting a common target site in plants can be quite different than in animals. What may be a lethal event in plants, eg inhibition of HPPD, can have a beneficial effect in mammals, eg treatment for tyrosinemia type I. These chemicals also have low mammalian toxicity due to rapid metabolism and/or excretion of the herbicide from mammalian systems.
大多数现代除草剂对哺乳动物的毒性较低。这种安全性的原因之一是除草剂的靶位点在哺乳动物中通常不存在。已阐明的除草剂作用机制约有20种。其中，有些确实与哺乳动物有共同的靶位点。这些机制包括自由基的形成、原卟啉原氧化酶（PROTOX）、谷氨酰胺合成酶（GS）和4-羟基苯丙酮酸双加氧酶（HPPD）。已表明PROTOX、HPPD和GS抑制剂在植物和哺乳动物中均能抑制这些酶，并且在哺乳动物系统中有可测量的影响。然而，抑制植物中共同靶位点的后果可能与动物中的大不相同。在植物中可能是致命的事件，例如抑制HPPD，在哺乳动物中可能产生有益的效果，例如用于治疗I型酪氨酸血症。由于除草剂在哺乳动物系统中快速代谢和/或排泄，这些化学物质对哺乳动物的毒性也较低。
