Moser V C, Scimeca J A, Balster R L
Neurotoxicology. 1985 Spring;6(1):35-42.
Most laboratory animal studies of the behavioral or neurophysiological effects of repeated exposures to volatile organic solvents find little evidence for substantial tolerance. This study examined the development of tolerance to the effects of 1,1,1-trichloroethane (1,1,1-TCE) on fixed-ratio responding in four mice. The subjects were exposed to 6000 ppm solvent vapor for 20 min of the daily 45-min operant sessions. Once a week, a series of four concentrations (1000-8000 ppm) were substituted for the daily exposure in order to obtain a cumulative concentration-effect curve. This proved to be a rapid and reliable method with which to ascertain the effects of 1,1,1-TCE over a range of concentrations. During the 15 days of 20-min exposure, the subjects showed a slight but significant increase in both response rates during exposure and in the rate of recovery following exposure. Maximal changes in these measures were evident in the first 7 days, with no further decreased sensitivity over the final 8 days of exposure. The concentration-effect curves determined during and after the daily exposures showed no significant shifts in either direction from the initial curve. Thus, while some alteration in the daily acute effects was noted, this tolerance was not of large magnitude and could not be detected as a change in the concentration-effect curve.
大多数关于反复接触挥发性有机溶剂的行为或神经生理效应的实验动物研究几乎没有发现明显耐受性的证据。本研究考察了四只小鼠对1,1,1 - 三氯乙烷（1,1,1-TCE）在固定比率反应上的耐受性发展情况。实验对象在每天45分钟的操作性实验环节中，暴露于6000 ppm的溶剂蒸汽中20分钟。每周一次，用一系列四种浓度（1000 - 8000 ppm）替代每日暴露，以获得累积浓度 - 效应曲线。事实证明，这是一种快速且可靠的方法，可用于确定一系列浓度下1,1,1-TCE的效应。在20分钟暴露的15天里，实验对象在暴露期间的反应率以及暴露后的恢复率均呈现轻微但显著的增加。这些指标的最大变化在前7天很明显，在暴露的最后8天里敏感性没有进一步降低。每日暴露期间和之后测定的浓度 - 效应曲线与初始曲线相比，在两个方向上均未显示出显著偏移。因此，虽然注意到每日急性效应有一些改变，但这种耐受性程度不大，无法作为浓度 - 效应曲线的变化被检测到。
