Szczesny Grzegorz, Veihelmann Andreas, Massberg Steffen, Nolte Dirk, Messmer Konrad
Department of Surgical Research and Transplantology, Polish Academy of Sciences, Warsaw, Poland.
Lab Anim. 2004 Jan;38(1):64-9. doi: 10.1258/00236770460734416.
The aim of this study was to establish a simple and safe method of anaesthesia for intravital microcirculatory observations in small laboratory animals. The usefulness of isoflurane inhalation anaesthesia has been investigated in different strains of mice commonly used in experimental medicine. These were the hairless (hr/hr, n = 12), the BALB/c (n = 12) and the nude mouse (nu/nu, n = 3). Anaesthesia was maintained by mask inhalation of isoflurane vaporized at concentrations of up to 4% in the induction phase, at 1.5% during acute surgical procedures and at 0.8-1.3% during prolonged experimental observations. Isoflurane was vapoured in a N(2)O/O(2) mixture and saturated with 32-36% F(i)O(2). During observations the body temperature was kept constant at 37 degrees C. The tail artery was cannulated for monitoring of mean arterial blood pressure (MAP) and heart rate (HR). To maintain the body fluid balance, isotonic saline was administered at a constant rate of 0.2 ml/h. Arterial blood samples were drawn for blood-gas analysis at the end of the experiments. All animals survived the anaesthesia protocol lasting between 3 and 6.5 h. During isoflurane inhalation, no breathing complications or changes in systemic circulatory parameters were observed. Mean values of MAP and HR were 79+/- 3 mmHg and 486+/- 13 min(-1), respectively, over the entire observation period. A moderate acidosis was recorded in animals under isoflurane anaesthesia, with alterations of arterial blood pH, p(a)O(2) and pCO(2) values (7.29+/- 0.06, 130+/- 19 mmHg and 35.6+/- 4.7 mmHg, respectively). In conclusion, inhalation anaesthesia with isoflurane is useful for experimental studies in the mouse due to (1) the simplicity of administration of the anaesthetic, (2) the rapid induction of anaesthesia, (3) easy control of the depth of anaesthesia, (4) the low percentage of complications, and (5) stable MAP and HR during observations lasting several hours. The proposed technique is especially suitable for observations of the microcirculation under intravital fluorescence microscopy.
本研究的目的是建立一种简单、安全的麻醉方法，用于小型实验动物的活体微循环观察。已在实验医学中常用的不同品系小鼠中研究了异氟烷吸入麻醉的效用。这些小鼠包括无毛小鼠（hr/hr，n = 12）、BALB/c小鼠（n = 12）和裸鼠（nu/nu，n = 3）。麻醉诱导期通过面罩吸入浓度高达4%的异氟烷维持，急性手术过程中为1.5%，长时间实验观察期间为0.8 - 1.3%。异氟烷在N₂O/O₂混合气体中汽化，并饱和32 - 36%的F(i)O₂。观察期间，体温保持在37℃恒定。通过尾动脉插管监测平均动脉血压（MAP）和心率（HR）。为维持体液平衡，以0.2 ml/h的恒定速率给予等渗盐水。实验结束时采集动脉血样本进行血气分析。所有动物均在持续3至6.5小时的麻醉方案中存活。在异氟烷吸入期间，未观察到呼吸并发症或全身循环参数的变化。在整个观察期内，MAP和HR的平均值分别为79 ± 3 mmHg和486 ± 13次/分钟。在异氟烷麻醉下的动物中记录到中度酸中毒，动脉血pH、p(a)O₂和pCO₂值发生改变（分别为7.29 ± 0.06、130 ± 19 mmHg和35.6 ± 4.7 mmHg）。总之，异氟烷吸入麻醉对小鼠实验研究有用，原因如下：（1）麻醉给药简单；（2）麻醉诱导迅速；（3）麻醉深度易于控制；（4）并发症发生率低；（5）在持续数小时的观察期间MAP和HR稳定。所提出的技术特别适用于活体荧光显微镜下的微循环观察。
