Modulation of nociceptive withdrawal reflexes evoked by single and repeated nociceptive stimuli in conscious dogs by low-dose acepromazine
Modulation of nociceptive withdrawal reflexes evoked by single and repeated nociceptive stimuli in conscious dogs by low-dose acepromazine
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DOI：
10.1111/j.1467-2995.2009.00447.x
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发表时间：
2009-05-01
影响因子：
1.7
通讯作者：
Spadavecchia, Claudia
中科院分区：
文献类型：
--
作者：
Bergadano, Alessandra;Andersen, Ole K.;Spadavecchia, Claudia
目的：研究小剂量乙酰丙嗪（ACP）对清醒犬伤害性退缩反射（NWR）和时间总和效应（TS）的调制作用。为了评估反射阈值的短期和长期稳定性，采用随机、盲法、安慰剂对照的交叉实验研究，8只成年雄性比格犬，通过单次经皮电刺激尺神经诱发NWR。重复刺激（10个脉冲，5 Hz），以诱发TS。三角肌的反应记录和量化的表面肌电图和行为反应进行了评分。每只犬每隔1周静脉注射0.01 mg/kg ACP或等体积生理盐水。在给药前（基线）和给药后20、60和100分钟进行测量。给药前和给药后每隔10分钟对镇静进行评分。采用Friedman重复测量秩和方差分析和Wilcoxon符号秩和检验进行数据分析，乙酰丙嗪导致轻度镇静，在注射后20分钟开始明显，在注射后30分钟达到峰值。单一（I（t））和重复刺激（TS（t））阈值强度，NWR和TS特征和行为反应在任何时间点都不受ACP的影响。I（t）和TS（t）均随时间而稳定。在狗中，0.01 mg kg（-1）ACP IV对由单一或重复刺激引起的NWR没有调节作用，表明对阶段性伤害性刺激没有抗伤害性感受活性。NWR阈值的稳定性的证据支持使用该模型作为一个客观的工具，调查在清醒的狗的伤害性感受。低剂量的ACP作为唯一的药物给药，可用于促进焦虑受试者的记录，而不改变该模型的有效性。
To investigate the modulation of the nociceptive withdrawal reflex (NWR) and temporal summation (TS) by low-dose acepromazine (ACP) in conscious dogs. To assess the short- and long-term stability of the reflex thresholds.Randomized, blinded, placebo-controlled cross-over experimental study.Eight adult male Beagles.The NWR was elicited using single transcutaneous electrical stimulation of the ulnar nerve. Repeated stimuli (10 pulses, 5 Hz) were applied to evoke TS. The responses of the deltoideus muscle were recorded and quantified by surface electromyography and the behavioural reactions were scored. Each dog received 0.01 mg kg(-1) ACP or an equal volume saline intravenously (IV) at 1 week intervals. Measurements were performed before (baseline) and 20, 60 and 100 minutes after drug administration. Sedation was scored before drug administration and then at 10 minutes intervals. Data were analyzed with Friedman repeated measures analysis of variance on ranks and Wilcoxon signed rank tests.Acepromazine resulted in a mild tranquilization becoming obvious at 20 minutes and peaking 30 minutes after injection. Single (I(t)) and repeated stimuli (TS(t)) threshold intensities, NWR and TS characteristics and behavioural responses were not affected by the ACP at any time point. Both I(t) and TS(t) were stable over time.In dogs, 0.01 mg kg(-1) ACP IV had no modulatory action on the NWR evoked by single or repeated stimuli, suggesting no antinociceptive activity on phasic nociceptive stimuli. The evidence of the stability of the NWR thresholds supports the use of the model as an objective tool to investigate nociception in conscious dogs. A low dose of ACP administered as the sole drug, can be used to facilitate the recordings in anxious subjects without altering the validity of this model.