The Effect of Chronic Nicotine and Its Withdrawal on ED_(50) Inspired Halothane Requirement in Rats

慢性尼古丁及其戒斷時對大白鼠吸氣百分之五十Halothane需求量之影響

楊靖宇(Ching-Yue Yang) ； 吳聞咸(Wen-Hsein Wu) ； Vlasta K. Zbuzek

《Acta Anaesthesiologica Sinica》 35卷2期 (1997/06) Pp. 73-77

摘要

Background: Based on previously observed antinociceptive effect of chronic nicotine treatment in rats, the authors measured the ED_(50) inspired halothane concentrations in rats having withdrawn from chronically infused nicotine, and in control rats. Methods: Rats in nicotine group (n = 19) were chronically exposed to nicotine (6 mg/kg/day for 28 days) infusion via Alzet osmotic pumps. Those in the control group (n = 16) were subjected to a sham operation. In each group, half of the rats was used one month later to explore the effect of nicotine withdrawal. Halothane in oxygen was delivered at a rate of 2 L/min to a box measured 2,912 cm^3. The ED_(50) halothane concentration, measured by mass spectrophotometry, was a midway gas tension at which 50% of rats responded to the tail pinching applied to the distal third of the tail for 30 s. Results: In nicotine group, the results showed a lower concentration of ED_(50) inspired halothane on days 1 and 3 in the first week (p ＜ 0.05). In the control group, repeated exposures to halothane gradually decreased the ED_(50), reaching the lowest value on day 7 (p ＜ 0.05 compared to day 1). Nicotine withdrawal did not alter the ED_(50) concentration of halothane in test rats compared with control rats. Conclusions: We conclude that chronic nicotine infusion could temporarily decrease the ED_(50) concentration of inspired halothane, and withdrawal of nicotine did not modify the ED_(50) concentration of halothane. In addition, the ED_(50) halothane concentration might be influenced by stress.

關鍵字

Anesthetics, inhalation: halothane ； Nicotinic agonist: nicotine ； Pharmacodynamic: dose-response relationship, drug

並列摘要

背景：基於先前慢性尼古丁對大白鼠antinociceptive effect之觀察，作者測量慢性尼古丁灌注，戒毒及對照組大白鼠的halothane之吸氣ED_(50)。方法：尼古丁組之大白鼠（n=19）接受經Alzet osmotic pumps之慢性尼古丁灌注。對照組接受sham手術。每組半數之大白鼠一個月後進行尼古丁戒毒實驗。實驗時halothane混和氧氣以2 L/min的速率流入一個2913 cm^3之密閉透明方箱之中。halothane之ED_(50)是以mass spectrophotometry測量，而以50%之大白鼠對其尾巴後1/3被夾住持續30秒有反應時之halothane濃度為halothane之ED_(50)。結果：結果顯示在nicotine組，在第一個星期之第一和第三天，halothane之ED_(50)較低（p＜0.05）。在對照組，重複給與大白鼠halothane逐漸減少ED_(50)，在第七天抵達最低值（與第一天比較p＜0,05）。尼古丁戒毒與對照組比較並沒有改變halothane之ED_(50)。結論：（1）慢性尼古丁灌注能暫時減少halothane之吸氣ED_(50)。（2）尼古丁戒毒並沒有改變halothane之吸氣ED_(50)。（3）壓力或許會影響halothane之吸氣ED_(50)。

並列關鍵字

麻藥劑，吸入性：halothane ； 尼古丁致活劑：尼古丁 ； 藥效學：劑量與反應關係，藥物