开蓬及其结构类似物对对硝基苯磷酸酶的影响。

Effects of chlordecone and its structural analogs on p-nitrophenyl phosphatase.

作者信息

Bansal S K, Desaiah D

出版信息

Toxicol Lett. 1982 Jul;12(2-3):83-90. doi: 10.1016/0378-4274(82)90168-0.

Abstract

The effects of chlordecone, mirex, and four photoderivatives of mirex on K+-stimulated p-nitrophenyl phosphatase (KPNPPase) in rat brain synaptosomes were determined. Additionally, the effect of chlordecone on the substrate and K+ activation kinetics and the inhibition of KPNPPase at 17, 27, and 37 degrees C were determined. The sensitivity of KPNPPase to various chemicals was highly variable. Chlordecone was the most effective inhibitor with an IC50 of 6.2 X 10(-6)M. All other chemicals showed a maximum inhibition of 20% at 20 muM concentration. The order of inhibition at 20 muM concentration was chlordecone (100%) greater than 8-monohydro mirex (20%) greater than 2,8-dihydromirex (10%) greater than mirex (10%) greater than 10-monohydro mirex (9%) greater than 5,10-dihydro mirex (2%). Double reciprocal plots of the data obtained on the effect of chlordecone on the substrate and K+ activation kinetics showed that the Vmax and Km were decreased with respect to paranitrophenyl phosphate, while it was competitive inhibition with respect to K+ activation. Chlordecone inhibited KPNPPase more at 37 degrees C than at 27 degrees C and 17 degrees C suggesting a positive temperature effect. These results suggest that chlordecone is the most effective inhibitor among its structural analogs tested on KPNPPase in rat brain synaptosomes.

摘要

测定了开蓬、灭蚁灵以及灭蚁灵的四种光衍生物对大鼠脑突触体中钾离子刺激的对硝基苯磷酸酶（KPNPPase）的影响。此外，还测定了开蓬对底物和钾离子激活动力学的影响以及在17、27和37摄氏度下对KPNPPase的抑制作用。KPNPPase对各种化学物质的敏感性差异很大。开蓬是最有效的抑制剂，IC50为6.2×10⁻⁶M。所有其他化学物质在20μM浓度下的最大抑制率为20%。在20μM浓度下的抑制顺序为：开蓬（100%）＞8-单氢灭蚁灵（20%）＞2,8-二氢灭蚁灵（10%）＞灭蚁灵（10%）＞10-单氢灭蚁灵（9%）＞5,10-二氢灭蚁灵（2%）。关于开蓬对底物和钾离子激活动力学影响的数据的双倒数图表明，相对于对硝基苯磷酸，Vmax和Km降低，而相对于钾离子激活则为竞争性抑制。开蓬在37摄氏度下比在27摄氏度和17摄氏度下更能抑制KPNPPase，表明存在正温度效应。这些结果表明，在测试的大鼠脑突触体KPNPPase的结构类似物中，开蓬是最有效的抑制剂。