Pryor G T, Rebert C S
SRI International, Menlo Park, California 94025.
Neurotoxicology. 1992 Spring;13(1):225-34.
Solvent mixtures are ubiquitous in industrialized environments and are used frequently for recreational purposes. Toluene and hexane are common components of many solvent mixtures and have characteristic, but different, neurotoxic consequences. Interestingly, Takeuchi et al., (1981) reported that toluene attenuated the peripheral neuropathy caused by n-hexane, possibly by blocking its metabolism to 2,5-hexanedione (Perbellini, et al., 1982). To confirm such effects at higher concentrations and to examine effects on the central nervous system (CNS), four groups of 12 rats each were exposed to air, toluene (1200 ppm), hexane (4000 ppm), or a mixture of toluene (1200 ppm) and hexane (4,000 ppm) 14 hr/day for 9 weeks. A battery of behavioral and electrophysiologic tests was used to assess the functional consequences of their exposures. The battery consisted of measures of grip strength, locomotor gait and landing splay, sensory sensitivities during conditioned avoidance performance, the action potential of the ventral caudal nerve, and the brainstem auditory evoked response. Measures of peripheral nervous system functions (e.g., grip strength and conduction velocity) showed interactive effects like those reported by Takeuchi et al. Toluene greatly reduced the neuropathy caused by hexane. Hexane-induced abnormalities in central components of the brainstem response were much less reduced in the presence of toluene. There was no reciprocal action of hexane on the motor syndrome and hearing loss caused by toluene.
溶剂混合物在工业化环境中无处不在，并且经常被用于娱乐目的。甲苯和己烷是许多溶剂混合物的常见成分，它们具有独特但不同的神经毒性后果。有趣的是，竹内等人（1981年）报告称，甲苯可减轻正己烷引起的周围神经病变，可能是通过阻断其代谢为2,5 -己二酮（佩贝利尼等人，1982年）。为了在更高浓度下证实这种效应并研究对中枢神经系统（CNS）的影响，将四组每组12只大鼠每天14小时暴露于空气、甲苯（1200 ppm）、己烷（4000 ppm）或甲苯（1200 ppm）与己烷（4000 ppm）的混合物中，持续9周。使用一系列行为和电生理测试来评估它们暴露后的功能后果。该测试包括握力、运动步态和着陆张度的测量、条件性回避行为期间的感觉敏感性、尾侧腹神经的动作电位以及脑干听觉诱发电位。周围神经系统功能的测量（如握力和传导速度）显示出与竹内等人报告的类似的交互作用。甲苯大大减轻了己烷引起的神经病变。在存在甲苯的情况下，己烷诱导的脑干反应中枢成分异常的减轻程度要小得多。己烷对甲苯引起的运动综合征和听力损失没有反向作用。
