Kaneko M, Saito Y, Kirihara Y, Kosaka Y
Department of Anesthesiology, Shimane Medical University, Izumo, Japan.
Br J Anaesth. 1994 Jun;72(6):657-61. doi: 10.1093/bja/72.6.657.
We have compared the antinociceptive effect of extradural lignocaine on somatic and visceral nociception in pregnant (n = 11) and non-pregnant rats (n = 9). Colorectal distension (CD) threshold and tail flick (TF) latency were measured as visceral and somatic nociception, respectively, for 60 min after extradural injection. On days 19, 20 and 21 of pregnancy, rats received lignocaine 200, 400 or 800 micrograms or normal saline via a chronically implanted lumbar extradural catheter. Extradural lignocaine produced dose-dependent antinociceptive effects on TF latency and CD threshold. Lignocaine 200 or 400 micrograms produced significantly greater peak effects in pregnant than in non-pregnant rats. Although the peak effects with lignocaine 800 micrograms were not different between groups, the duration of the effects were longer in pregnant compared with non-pregnant rats. We conclude that both somatic and visceral antinociceptive effects of extradural lignocaine were potentiated in pregnant rats near term compared with those in non-pregnant rats.
我们比较了硬膜外利多卡因对怀孕大鼠（n = 11）和未怀孕大鼠（n = 9）的躯体和内脏伤害感受的镇痛作用。硬膜外注射后60分钟内，分别测量结肠扩张（CD）阈值和甩尾（TF）潜伏期作为内脏和躯体伤害感受指标。在妊娠第19、20和21天，大鼠通过长期植入的腰段硬膜外导管接受200、400或800微克利多卡因或生理盐水。硬膜外利多卡因对TF潜伏期和CD阈值产生剂量依赖性镇痛作用。200或400微克利多卡因对怀孕大鼠产生的峰值效应明显大于未怀孕大鼠。虽然800微克利多卡因组间的峰值效应无差异，但与未怀孕大鼠相比，怀孕大鼠的效应持续时间更长。我们得出结论，与未怀孕大鼠相比，接近足月的怀孕大鼠硬膜外利多卡因的躯体和内脏镇痛作用均增强。
