Danneman P J, White W J, Marshall W K, Lang C M
Department of Comparative Medicine, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033.
Lab Anim Sci. 1988 Feb;38(1):51-7.
The immobility response (IR) was studied in rabbits to evaluate its analgesic properties and reliability as a method of restraint. The participation of the endogenous opioid system in IR was studied indirectly by evaluating the effects of the narcotic antagonist naloxone on this phenomenon. Twenty-four adult New Zealand White rabbits were subjected to six noxious stimuli while restrained by IR and while restrained under control conditions. Testing on each animal was repeated under both conditions following the administration of naloxone. The noxious stimuli consisted of three levels of electric shock (10 volts, 30 volts, and 50 volts) applied to the shaved forearm, and mechanical pressure applied to the pinna, front toe, and hind toe. Withdrawal and changes in blood pressure, heart rate, and respiration were used as indicators of pain perception. Distress associated with noxious electrical and pressure stimulation was significantly reduced by IR, which suggested that the phenomenon does have a significant analgesic component. However, the rabbits showed wide variability in their susceptibility to IR induction, and even animals which did not withdraw in response to noxious stimulation under IR sometimes exhibited physiological changes suggestive of distress. Therefore, IR should not be considered as a reliable or humane alternative to analgesic/anesthetic drugs for laboratory rabbits. Naloxone had little effect on IR or IR-associated analgesia.
对家兔的不动反应（IR）进行了研究，以评估其镇痛特性以及作为一种约束方法的可靠性。通过评估麻醉拮抗剂纳洛酮对该现象的影响，间接研究了内源性阿片系统在IR中的作用。将24只成年新西兰白兔在IR约束下以及在对照条件下约束时接受六种有害刺激。在给予纳洛酮后，在两种条件下对每只动物进行重复测试。有害刺激包括施加于剃毛前臂的三个强度等级的电击（10伏、30伏和50伏），以及施加于耳廓、前趾和后趾的机械压力。退缩以及血压、心率和呼吸的变化被用作疼痛感知的指标。IR显著降低了与有害电刺激和压力刺激相关的痛苦，这表明该现象确实具有显著的镇痛成分。然而，家兔对IR诱导的易感性表现出很大差异，甚至在IR下对有害刺激无退缩反应的动物有时也表现出提示痛苦的生理变化。因此，对于实验用家兔，IR不应被视为替代镇痛/麻醉药物的可靠或人道方法。纳洛酮对IR或与IR相关的镇痛作用影响很小。
