Monroy-Noyola Antonio, Rojas Patricia, Vilanova Eugenio, Sogorb Miguel A
Laboratorio de Neuroprotección, Facultad de Farmacia, Universidad Autónoma del Estado de Morelos, Universidad 1001 Chamilpa, C.P. 62210, Cuernavaca, México.
Arch Toxicol. 2007 Oct;81(10):689-95. doi: 10.1007/s00204-007-0197-2. Epub 2007 Mar 30.
The Ca(2+)-dependent and EDTA-resistant hydrolysis of O-hexyl O-2,5-dichlorophenyl phosphoramidate (HDCP) and paraoxon was studied in serum and subcellular fractions of liver, kidney and brain of hen, rat and rabbit. HDCP was the best substrate among all the tissues studied, except that of rabbit serum which showed the highest Ca(2+)-dependent paraoxon hydrolysing activity (paraoxonase). High HDCP hydrolysing activity (HDCPase) was detected in the brain tissue of the three species studied, whereas low or no paraoxonase was found. The HDCPase/paraoxonase ratio of Ca(2+)-dependent hydrolysing activities ranged from 0.5 to 83 for tissues of the same species. EDTA-resistant HDCPase activity was more than 50% of the total activities in hen tissues, with an almost undetectable Ca(2+)-dependent paraoxonase activity in most organs. The same response was observed in rat tissues, except for serum where the Ca(2+)-dependent HDCPase and paraoxonase activities were higher (70 and 25% of total activities, respectively). EDTA-resistant HDCPase and paraoxonase activities represented less than 25% of all activities in rabbit tissues. Paraoxon has traditionally been the substrate for measuring organophosphorus hydrolysing activities. However, HDCP could be a good substrate in addition to paraoxon for monitoring other phosphotriesterases in biological tissues.
在母鸡、大鼠和兔子的肝脏、肾脏及脑组织的血清和亚细胞组分中，研究了O-己基O-2,5-二氯苯基氨基磷酸酯（HDCP）和对氧磷的钙依赖性及乙二胺四乙酸（EDTA）抗性水解。在所有研究的组织中，HDCP是最佳底物，但兔血清除外，兔血清表现出最高的钙依赖性对氧磷水解活性（对氧磷酶）。在所研究的三种动物的脑组织中均检测到高HDCP水解活性（HDCP酶），而对氧磷酶活性较低或未检测到。同一物种组织中，钙依赖性水解活性的HDCP酶/对氧磷酶比率在0.5至83之间。在母鸡组织中，EDTA抗性HDCP酶活性超过总活性的50%，大多数器官中钙依赖性对氧磷酶活性几乎检测不到。在大鼠组织中也观察到相同的反应，但血清除外，血清中钙依赖性HDCP酶和对氧磷酶活性较高（分别占总活性的70%和25%）。在兔组织中，EDTA抗性HDCP酶和对氧磷酶活性占所有活性的比例不到25%。传统上，对氧磷一直是用于测量有机磷水解活性的底物。然而，除对氧磷外，HDCP可能是监测生物组织中其他磷酸三酯酶的良好底物。
