de Souza Dyer Cecilia, Brice Angela K, Marx James O
University Laboratory Animal Resources, Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
University Laboratory Animal Resources, Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania;, Email:
J Am Assoc Lab Anim Sci. 2017 May 1;56(3):299-306.
The humane euthanasia of animals in research is of paramount importance. Neonatal mice frequently respond differently to euthanasia agents when compared with adults. The AVMA's Guidelines for the Euthanasia of Animals includes intraperitoneal injection of ethanol as "acceptable with conditions," and recent work confirmed that this method is appropriate for euthanizing adult mice, but neonatal mice have not been tested. To explore this method in neonatal mice, mouse pups (C57BL/6 and CD1, 162 total) were injected with 100% ethanol, a pentobarbital-phenytoin combination, or saline at 7, 14, 21, 28, or 35 d of age. Electrocardiograms, respiratory rates, and times to loss of righting reflex and death were recorded. Time to death (TTD) differed significantly between ethanol and pentobarbital-phenytoin at 7, 14, and 21 d and between ethanol groups at 7, 14, and 21 d compared with 35 d. The average TTD (± 1 SD) for ethanol-injected mice were: 7 d, 70.3 ± 39.8 min; 14 d, 51.7 ± 30.5 min; 21 d, 32.3 ± 20.8 min, 28 d, 14.0 ± 15.2; and 35 d, 4.9 ± 1.4. Mean TTD in pentobarbital-phenytoin-injected mice were: 7 d, 2.8 ± 0.4 min; 14 d, 2.9 ± 0.5 min; 21 d, 3.9 ± 1.2 min; 28 d, 3.9 ± 0.7 min; and 35 d, 4.4 ± 0.5. Although TTD did not differ between ethanol and pentobarbital-phenytoin at 28 d of age, the TTD in 3 of 12 mice was longer than 15 min after ethanol administration at this age. Therefore, ethanol should not be used as a method of euthanasia for mice younger than 35 d, because the criteria for humane euthanasia were met only in mice 35 d or older.
在研究中对动物进行人道安乐死至关重要。与成年小鼠相比，新生小鼠对安乐死药物的反应常常不同。美国兽医协会的《动物安乐死指南》将腹腔注射乙醇列为“在一定条件下可接受”的方法，最近的研究证实该方法适用于对成年小鼠实施安乐死，但尚未对新生小鼠进行测试。为了在新生小鼠中探究这种方法，在出生后7、14、21、28或35天，给幼鼠（共162只，品系为C57BL/6和CD1）注射100%乙醇、戊巴比妥 - 苯妥英钠合剂或生理盐水。记录心电图、呼吸频率以及翻正反射消失和死亡的时间。在7、14和21天时，乙醇组和戊巴比妥 - 苯妥英钠组之间的死亡时间（TTD）存在显著差异，并且在7、14和21天时，乙醇组之间的TTD与35天时相比也有差异。注射乙醇的小鼠的平均TTD（±1标准差）分别为：7天，70.3±39.8分钟；14天，51.7±30.5分钟；21天，32.3±20.8分钟；28天，14.0±15.2分钟；35天，4.9±1.4分钟。注射戊巴比妥 - 苯妥英钠的小鼠的平均TTD分别为：7天，2.8±0.4分钟；14天，2.9±0.5分钟；21天，3.9±1.2分钟；28天，3.9±0.7分钟；35天，4.4±0.5分钟。尽管在28天时乙醇组和戊巴比妥 - 苯妥英钠组之间的TTD没有差异，但在这个年龄，12只小鼠中有3只在注射乙醇后TTD超过15分钟。因此，乙醇不应作为35日龄以下小鼠的安乐死方法，因为只有35日龄及以上的小鼠才符合人道安乐死的标准。
