Spiss C K, Smith C M, Maze M
Anesth Analg. 1984 Sep;63(9):825-8.
The incidence of halothane-epinephrine arrhythmias increases after the short-term administration of imipramine, probably because of enhanced noradrenergic transmission. To determine whether this effect persists after long-term imipramine treatment, we have studied the arrhythmogenicity and adrenergic responsiveness in halothane anesthetized dogs after six weeks of imipramine administration, 150 mg X day-1, orally. The mean (+/- SD) arrhythmogenic dose of epinephrine (ADE) in nine dogs anesthetized with 1.2 MAC halothane was 2.57 (+/- 1.04) micrograms X kg-1 X min-1. The alpha-adrenergic responsiveness, assessed as the dose of phenylephrine that caused a 75% increase in mean arterial pressure (alpha 75), was 5.78 +/- 2.39 micrograms X kg-1 X min-1. The dose of isoproterenol that increased heart rate by 75% (beta 75) was 309 +/- 180 ng X kg-1 X min-1. After imipramine treatment, the ADE (2.63 +/- 1.26), alpha 75 (5.16 +/- 2.05), and beta 75 (386 +/- 266) were not statistically different from the pre-imipramine values (P greater than 0.05), despite a fivefold increase in circulating norepinephrine. We conclude that chronic imipramine does not alter arrhythmogenicity and adrenergic responsiveness, since compensatory mechanisms, at the sympathetic nerve terminal, may revert the initial hyper-responsiveness to normal.
短期给予丙咪嗪后，氟烷-肾上腺素性心律失常的发生率增加，这可能是由于去甲肾上腺素能传递增强所致。为了确定长期丙咪嗪治疗后这种效应是否持续存在，我们研究了口服丙咪嗪150mg/天，持续六周后，氟烷麻醉犬的心律失常发生性和肾上腺素能反应性。9只接受1.2MAC氟烷麻醉的犬，肾上腺素的平均（±标准差）致心律失常剂量（ADE）为2.57（±1.04）μg·kg⁻¹·min⁻¹。以去氧肾上腺素使平均动脉压升高75%时的剂量（α75）评估的α-肾上腺素能反应性为5.78±2.39μg·kg⁻¹·min⁻¹。使心率增加75%的异丙肾上腺素剂量（β75）为309±180ng·kg⁻¹·min⁻¹。丙咪嗪治疗后，ADE（2.63±1.26）、α75（5.16±2.05）和β75（386±266）与丙咪嗪治疗前的值相比无统计学差异（P＞0.05），尽管循环去甲肾上腺素增加了五倍。我们得出结论，慢性丙咪嗪不会改变心律失常发生性和肾上腺素能反应性，因为交感神经末梢的代偿机制可能会使最初的高反应性恢复正常。
