Smith Jennifer C, Corbin Timothy J, McCabe James G, Bolon Brad
Department of Laboratory Animal Resources, Amgen Inc., Thousand Oaks, California, USA.
Lab Anim. 2004 Jan;38(1):38-43. doi: 10.1258/00236770460734371.
During our initial attempts to produce transgenic rats, we found that an anaesthetic combination typically used for embryo transfer (intramuscular injection of ketamine [90 mg/kg] with xylazine [10 mg/kg]) yielded extensive variation in both the depth and length of anaesthesia. In the present prospective study, we compared the reproductive outcomes afforded by using either isoflurane (5% for induction, 2% for maintenance, carried in 2 l/min of oxygen) with morphine (5 mg/kg s.c., given immediately after isoflurane induction) or ketamine/xylazine in adult (250-300 g), pseudopregnant Sprague-Dawley rats. Each animal was anaesthetized with either isoflurane/morphine or ketamine/xylazine, after which 30 microinjected eggs were transferred into the left uterine horn. The mean pregnancy rate for isoflurane/morphine (15%) was 50% greater than that achieved with ketamine/xylazine (10%). The mean number of live pups (just over five per litter) was comparable for both regimens. All rats given isoflurane/morphine quickly achieved a surgical depth of anaesthesia and experienced a rapid postoperative recovery (3-5 min). In contrast, 25% of rats injected with ketamine/xylazine did not reach a depth of anaesthesia within 10 min that was sufficient for laparotomy, and all that were anaesthetized successfully required an extended postoperative recovery period (60-90 min). These data show that isoflurane/morphine is well tolerated by microinjected embryos and suggest that its use during embryo transfer may provide a means for both reducing the number of pseudopregnant females used and increasing the speed with which rat transgenic projects are completed.
在我们最初尝试培育转基因大鼠的过程中，我们发现一种通常用于胚胎移植的麻醉组合（肌肉注射氯胺酮[90毫克/千克]与赛拉嗪[10毫克/千克]）在麻醉深度和时长方面都产生了很大差异。在本前瞻性研究中，我们比较了在成年（250 - 300克）假孕的斯普拉格 - 道利大鼠中使用异氟烷（诱导时5%，维持时2%，以2升/分钟的氧气为载体）联合吗啡（皮下注射5毫克/千克，在异氟烷诱导后立即给予）或氯胺酮/赛拉嗪所带来的生殖结果。每只动物用异氟烷/吗啡或氯胺酮/赛拉嗪麻醉，之后将30个显微注射的卵转移到左子宫角。异氟烷/吗啡组的平均妊娠率（15%）比氯胺酮/赛拉嗪组（10%）高50%。两种方案下每窝存活幼崽的平均数量（每窝略超过5只）相当。所有接受异氟烷/吗啡麻醉的大鼠很快达到手术麻醉深度，术后恢复迅速（3 - 5分钟）。相比之下，注射氯胺酮/赛拉嗪的大鼠中有25%在10分钟内未达到足以进行剖腹手术的麻醉深度，所有成功麻醉的大鼠术后恢复期都延长了（60 - 90分钟）。这些数据表明显微注射的胚胎对异氟烷/吗啡耐受性良好，并表明在胚胎移植过程中使用它可能为减少假孕雌性大鼠的使用数量以及加快大鼠转基因项目的完成速度提供一种方法。
