Vale J A
National Poisons Information Service, and Centre for Chemical Incidents, City Hospital NHS Trust, Birmingham, UK.
Toxicol Lett. 1998 Dec 28;102-103:649-52. doi: 10.1016/s0378-4274(98)00277-x.
As the majority of OP insecticides are lipophilic and not ionised they are absorbed rapidly following inhalation or ingestion; dermal absorption is slower but severe poisoning may still ensue if exposure is prolonged. Following absorption, OP compounds accumulate in fat, liver, kidneys and salivary glands. Phosphates (P=O) are biologically active as AChE inhibitors, whereas phosphorothioates (P=S) need bioactivation to their phosphate anologues (oxons) to become biologically active. Oxons inhibit AChE by phosphorylation of the serine hydroxyl group in the substrate-binding domain of the enzyme. The rate of spontaneous reactivation of alkyl phosphorylated AChE depends on the chemical structure of the OP compound. Spontaneous reactivation of dimethyl phosphorylated AChE proceeds quite rapidly. However, unless oximes are employed, there is no such expectation of rapid recovery for patients intoxicated with diethyl phosphoryl insecticides.
由于大多数有机磷杀虫剂具有亲脂性且未离子化，它们在吸入或摄入后会迅速被吸收；经皮肤吸收较慢，但如果接触时间延长，仍可能导致严重中毒。吸收后，有机磷化合物会在脂肪、肝脏、肾脏和唾液腺中蓄积。磷酸盐（P=O）作为乙酰胆碱酯酶抑制剂具有生物活性，而硫代磷酸酯（P=S）需要生物活化成为其磷酸盐类似物（氧磷）才具有生物活性。氧磷通过使酶底物结合域中的丝氨酸羟基磷酸化来抑制乙酰胆碱酯酶。烷基磷酸化乙酰胆碱酯酶的自发重新活化速率取决于有机磷化合物的化学结构。二甲基磷酸化乙酰胆碱酯酶的自发重新活化进行得相当快。然而，除非使用肟类药物，否则对于因二乙基磷酰基杀虫剂中毒的患者，无法期望其迅速恢复。
