Crofton K M, Kehn L S, Gilbert M E
Neurotoxicology Division, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
Neurotoxicol Teratol. 1995 Jul-Aug;17(4):489-95. doi: 10.1016/0892-0362(95)00008-f.
Deltamethrin is a potent neuroactive pyrethroid insecticide. Literature reports of the in vivo potency of deltamethrin, however, vary by greater than three orders of magnitude in studies employing numerous vehicles and routes of exposure. Therefore, the present study systematically compared IP and PO routes of exposure to deltamethrin (0.3-1000 mg/kg) delivered to adult rats in one of four different vehicles (corn oil, glycerol formal, Emulphor, or methylcellulose). A reduction in motor activity as measured in figure-8 mazes was used to index the potency of this pesticide on CNS function. Dose-effect and time-course determinations were made for each combination of vehicle and route. Results demonstrated that the potency of deltamethrin was dependent on both the route of administration and the vehicle. The ED50 for deltamethrin was 5.1 mg/kg when administered PO in corn oil, whereas, the ED50 was > 1000 mg/kg when administered PO in methylcellulose. Thus, reported discrepancies in the potency of deltamethrin on CNS function are at least partially attributable to route of administration and vehicle.
溴氰菊酯是一种强效的神经活性拟除虫菊酯类杀虫剂。然而，在采用多种赋形剂和暴露途径的研究中，关于溴氰菊酯体内效力的文献报道相差超过三个数量级。因此，本研究系统地比较了成年大鼠经腹腔注射（IP）和口服（PO）途径暴露于溴氰菊酯（0.3 - 1000 mg/kg）的情况，溴氰菊酯以四种不同赋形剂（玉米油、甲醛甘油、乳化剂或甲基纤维素）之一给药。通过测量“8”字形迷宫中的运动活动减少来评估这种农药对中枢神经系统（CNS）功能的效力。对每种赋形剂和给药途径的组合进行剂量效应和时间进程测定。结果表明，溴氰菊酯的效力取决于给药途径和赋形剂。当在玉米油中口服给药时，溴氰菊酯的半数有效剂量（ED50）为5.1 mg/kg，而在甲基纤维素中口服给药时，ED50 > 1000 mg/kg。因此，关于溴氰菊酯对中枢神经系统功能效力的报道差异至少部分归因于给药途径和赋形剂。
