Spontaneous Reactivation And Aging Of AChE Inhibited By Paraoxon And Malaoxon In11Species

In this study, the AChE of Resistant Plutella xylostella(L.), Susceptible Plutella xylostella(L.), Phyllotreta striolata, Propylea japonica, Cotesiaplutellae, Mouse, Pteromalus puparum, Carassius auratus, Musca domestica, Prodenia litura and Leptodactylidae were inhibited by paraoxon and malaoxon, the toxicity of AChE from the11species inhibited by paraoxon and malaoxon were determined, and the I50and the I90were calculated. Then the AChE was inhibited by paraoxon and malaoxon in the concentration of I90. After the inhibition time was up, removal of the excess inhibitor with reversed-phase silica to determine spontaneous reactivation and aging. The rate constants of spontaneous reactivation were estimated from the ratio of enzyme activities at different times. The rate constants of aging were estimated from the ratio of enzyme activities, which has incubation with TMB-4(0.1mmol/L) to reactivation, at different times. All the reaction were performed at25℃. The major results of this thesis showed that:1. The species-related differences of sensitivity in the inhibition of AChE by paraoxon is more large than by malaoxon.2. The AChE from mouse is high sensitive to paraoxon and it is low sensitive to malaoxon.3. The rate constants of spontaneous reactivation and aging from phosphorylated-AChE are not related to the sensitivity of AChE to inhibition by OP pesticides, so the two constants can’t be served as a standard to the pest resistance.4. The spontaneous reactivation of phosphorylated-AChE from the Coleoptera insects may be greater than from other insects.5. The spontaneous reactivation of phosphorylated-AChE from mammal is much greater than from insect.6. The rate constants of aging from AChE inhibited by malaoxon are greater than by paraoxon. The fact showed that the rate constants of aging is related to the species of OP pesticides.7. The rate constants of aging from phosphorylated-AChE which inhibited by paraoxon and malaoxon from insects are greater than the spontaneous reactivation rate constants. However, the poisoned AChE of insects is easier to aging than to spontaneous reactivation.