Is There a Cutoff in Anesthetic Potency for the Normal Alkanes?
Is There a Cutoff in Anesthetic Potency for the Normal Alkanes?
复制标题
正烷烃的麻醉效力是否存在截止值？
DOI：
10.1213/00000539-199307000-00004
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发表时间：
1993
影响因子：
5.7
通讯作者：
M. Halsey
中科院分区：
文献类型：
--
作者：
Jin Liu;M. Laster;S. Taheri;E. Eger;D. Koblin;M. Halsey
测定了连续10个正构烷烃、甲烷至正庚烷大鼠的蒸汽压和麻醉分压。所有动物都产生了麻醉，定义为对尾巴夹子或对尾巴进行电刺激时不动。麻醉分压计算为仅允许运动和阻止运动的浓度之间的平均值。尽管在饱和蒸汽压下，正庚烷和正十一烷单独给药时不能提供麻醉，但它们的麻醉特性可以通过它们减少异氟烷的麻醉需求的能力来证明(即，它们的麻醉能力可以通过加法研究来确定)。随着链长的增加，麻醉剂的效力增加(甲烷从9.9atm增加到0.0142臂)，蒸汽压降低(乙烷从38.2atm下降到0.0028 atm)。蒸汽压的下降远远超过效价的增加。对于正庚烷和正庚烷，麻醉所需分压与饱和蒸气压之比小于1，分别为0.48和0.19。我们的结论是，从正构烷烃到正构烷烃不存在截断现象(即长链烷烃不存在麻醉效应)，但较大的烷烃的蒸汽压太低，无法在单独给药时显示其效力。
Vapor pressures and anesthetizing partial pressures in rats were measured for 10 consecutive normal alkanes, methane through decane. All produced anesthesia as defined by the absence of movement in response to either the application of a tail-clamp or electrical stimulation of the tail. The anesthetizing partial pressure was calculated as the average between the concentrations just permitting and preventing movement. Although nonane and decane did not provide anesthesia when given alone at their saturated vapor pressures, their anesthetic properties could be demonstrated by their ability to decrease the anesthetic requirement for isoflurane (i.e., their anesthetic potencies could be defined by studies of additivity). Anesthetic potency increased (from 9.9 arm for methane to 0.0142 arm for decane) and vapor pressure decreased (from 38.2 atm for ethane to 0.0028 atm for decane) with increasing chain length. The decrease in vapor pressure far exceeded the increase in potency. For nonane and decane, the ratio of the partial pressure required for anesthesia to the saturated vapor pressure was less than 1, being 0.48 and 0.19, respectively. We conclude that no cutoff phenomenon (i.e., no absence of anesthetic effect with longer chain alkanes) exists from n-methane to n-decane, but that larger alkanes have vapor pressures too low to permit their potency to be evident when given alone.