Department of Clinical Studies-Philadelphia, University of Pennsylvania, 3900 Delancey Street, Philadelphia, PA 19104, USA.
Lab Anim. 2010 Oct;44(4):323-8. doi: 10.1258/la.2010.010025. Epub 2010 Aug 16.
Urethane is often used as a sole anaesthetic agent for non-recovery studies in laboratory animals. However, the use of urethane is controversial, in part, because the electroencephalogram after urethane administration is similar to the electroencephalogram recorded from unanaesthetized animals. Here, we assessed the minimum alveolar concentration (MAC)-sparing effects of urethane by measuring the effect of two doses of urethane on the MAC of isoflurane in male Sprague Dawley rats. Isoflurane MAC was measured before and after intravenous administration of urethane at 1.0 g/kg (Group G₁, n = 6) and 1.5 g/kg (Group G₁.₅, n = 6), or an equal volume of 0.9% saline (Group Gs, n = 6). Baseline isoflurane MAC was not statistically different between groups (isoflurane concentration: 1.47 ± 0.08%, 1.40 ± 0.19% and 1.42 ± 0.12% for G₁, G₁.₅ and Gs, respectively). Intravenous injection of saline did not alter isoflurane MAC (post-saline MAC: 1.43 ± 0.11%). After urethane administration, isoflurane MAC decreased in a dose-dependent manner (new MAC G₁: 0.19 ± 0.06%; G₁.₅: 0.03 ± 0.01%; P < 0.05). The isoflurane MAC after 1.5 g/kg urethane was not significantly different from room air isoflurane concentrations (0.01 ± 0.01%), demonstrating a 100% MAC reduction at this dose. In conclusion, high-dose urethane (1.5 g/kg intravenously) was suitable as a sole anaesthetic agent to prevent gross purposeful movement during the conditions of the study, whereas low-dose urethane (1.0 g/kg intravenously) was not.
氨基甲酸乙酯通常用作非恢复性研究中实验室动物的单一麻醉剂。然而，氨基甲酸乙酯的使用存在争议，部分原因是氨基甲酸乙酯给药后的脑电图与未麻醉动物记录的脑电图相似。在这里，我们通过测量两种剂量的氨基甲酸乙酯对异氟醚最小肺泡浓度（MAC）的影响来评估氨基甲酸乙酯的 MAC 节省作用雄性斯普拉格-道利大鼠。在静脉注射 1.0 g/kg （G₁ 组，n = 6）和 1.5 g/kg （G₁.₅ 组，n = 6）氨基甲酸乙酯或等体积 0.9%生理盐水（Gs 组，n = 6）前后测量异氟醚 MAC。各组间基线异氟醚 MAC 无统计学差异（异氟醚浓度：G₁、G₁.₅ 和 Gs 分别为 1.47 ± 0.08%、1.40 ± 0.19%和 1.42 ± 0.12%）。静脉注射生理盐水不改变异氟醚 MAC（盐水后 MAC：1.43 ± 0.11%）。氨基甲酸乙酯给药后，异氟醚 MAC 呈剂量依赖性降低（新 MAC G₁：0.19 ± 0.06%；G₁.₅：0.03 ± 0.01%；P < 0.05）。1.5 g/kg 氨基甲酸乙酯后的异氟醚 MAC 与室内空气异氟醚浓度无显著差异（0.01 ± 0.01%），表明在此剂量下 MAC 降低 100%。总之，高剂量氨基甲酸乙酯（1.5 g/kg 静脉内）适合作为单一麻醉剂，以防止研究条件下的明显有目的运动，而低剂量氨基甲酸乙酯（1.0 g/kg 静脉内）则不然。
