Abstract

Background

The potent inhalational anesthetic isoflurane has widespread use in experimental investigations. Intratracheal administration of the agent attenuates breathing, blood pressure, heart rate, and baroreflex control of heart rate. Concurrent effects of potent inhalational anesthetics on hemodynamic waves and neural respiratory output have yet to be systematically interrogated.

Objectives

We sought to determine the effects of administering isoflurane to unanesthetized decerebrate animals upon breathing, dynamic arterial pressure magnitude, and ventricular depolarization frequency.

Methods and Results

Experiments were conducted on ten unanesthetized decerebrate Sprague-Dawley adult male rats. Saturation of a hyperoxic gas mixture with 2.0% isoflurane in supracollicularly decerebrate rats having undergone successful weaning from isoflurane anesthesia quantally reduced phrenic nerve bursting frequency and coupling with the ventilator cycle from 1:1 to 1:2 and prolonged phrenic expiratory duration, though failed to modify phrenic inspiratory burst amplitude or duration. Isoflurane also reduced dynamic arterial pressure magnitude and heart rate, increased heart rate variability, and reduced blood pressure variability.

Conclusions

Use of unanesthetized decerebrate preparations eschewing the confounding effects of anesthesia upon neural networks may prudently supplant the use of anesthetized animals when seeking to mechanistically interrogate propriobulbar interneuronal microcircuit oscillators constituting the respiratory rhythm and pattern generator, sympathetic oscillators, and cardiovagal premotoneurons.

中文翻译：

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异氟醚对去脑大鼠动脉血压、心率和膈神经放电的影响

摘要

背景

强效吸入麻醉剂异氟醚在实验研究中具有广泛的用途。药剂的气管内给药减弱呼吸、血压、心率和心率的压力反射控制。强效吸入麻醉剂对血流动力学波和神经呼吸输出的同时影响尚未得到系统研究。

目标

我们试图确定对未麻醉的去脑动物施用异氟醚对呼吸、动态动脉压幅度和心室去极化频率的影响。

方法和结果

对十只未麻醉的去大脑 Sprague-Dawley 成年雄性大鼠进行了实验。高氧气体混合物与 2.0% 异氟醚在已成功脱离异氟醚麻醉的上丘脑大鼠中饱和，可将膈神经爆裂频率和与呼吸机周期的耦合从 1:1 降至 1:2 并延长膈呼气持续时间，但未能修改膈吸气爆发幅度或持续时间。异氟醚还降低了动态动脉压幅度和心率，增加了心率变异性，并降低了血压变异性。

结论

当试图机械地询问构成呼吸节律和模式发生器、交感神经振荡器和心血管前运动神经元的球前神经元间微电路振荡器时，使用未麻醉的去大脑制剂避免麻醉对神经网络的混杂影响，可能会谨慎地取代使用麻醉动物。