Tsukamoto Atsushi, Niino Natsuko, Sakamoto Mizuho, Ohtani Risa, Inomata Tomo
Laboratory of Laboratory Animal Science, Azabu University, 1-17-71 Fuchinobe, Chuou-ku, Sagamihara-shi, Kanagawa 252-5201, Japan.
Exp Anim. 2018 Jul 30;67(3):329-336. doi: 10.1538/expanim.18-0003. Epub 2018 Mar 14.
To achieve surgical anesthesia in animal experimentation, it is necessary to select the appropriate anesthetic protocol by considering its pharmacological properties and the surgical procedure to be performed. However, few studies have investigated the validity of anesthetic protocols under surgical conditions in small rodents. The present study aimed to clarify the pharmacological properties of 4 anesthetic protocols during the surgical procedure of castration in rats. Eight-week-old male Wistar rats were anesthetized with anesthetics, including the combination of ketamine and xylazine (K/X), the combination of medetomidine, midazolam, and butorphanol (M/M/B), isoflurane, and sevoflurane. Castration was performed under each anesthesia, and anesthetic depth and times were assessed, as were vital signs. The injectable anesthetics were investigated at standard and high doses. The concentration of inhalant anesthetics was adjusted to 1.5 minimum alveolar concentration (MAC). K/X at both doses demonstrated sufficient anesthetic depth with rapid induction and recovery. However, bradycardia and hypothermia were prominent in high-dose K/X, indicating that the standard-dose is more appropriate for surgical anesthesia in castration procedures. M/M/B demonstrated high anesthetic sensitivity variation in individual animals. In contrast to injectable anesthetics, inhalant anesthetics provided stable anesthetic depth with less cardiorespiratory influence. Sevoflurane did not lead to a significant decrease in rectal temperature during the anesthetic period. Results of the present study revealed the optimal dose and pharmacological features of several anesthetic protocols for castration, and may contribute to the standardization of surgical anesthesia in rats.
在动物实验中要实现手术麻醉，有必要通过考虑其药理特性和即将进行的手术程序来选择合适的麻醉方案。然而，很少有研究调查小型啮齿动物在手术条件下麻醉方案的有效性。本研究旨在阐明4种麻醉方案在大鼠去势手术过程中的药理特性。8周龄雄性Wistar大鼠用麻醉剂进行麻醉，包括氯胺酮和赛拉嗪的组合（K/X）、美托咪定、咪达唑仑和布托啡诺的组合（M/M/B）、异氟烷和七氟烷。在每种麻醉下进行去势手术，并评估麻醉深度和时间以及生命体征。对注射用麻醉剂进行了标准剂量和高剂量研究。将吸入性麻醉剂的浓度调整至1.5最低肺泡浓度（MAC）。两种剂量的K/X均显示出足够的麻醉深度，诱导和恢复迅速。然而，高剂量K/X时心动过缓和体温过低较为突出，表明标准剂量更适合去势手术中的手术麻醉。M/M/B在个体动物中显示出较高的麻醉敏感性差异。与注射用麻醉剂相比，吸入性麻醉剂提供稳定的麻醉深度，对心肺的影响较小。七氟烷在麻醉期间未导致直肠温度显著下降。本研究结果揭示了几种去势麻醉方案的最佳剂量和药理特征，可能有助于大鼠手术麻醉的标准化。
