Sayiner A, Lorenz R R, Warner D O, Rehder K
Mayo Clinic, Rochester, Minnesota 55905.
Anesthesiology. 1991 Jul;75(1):75-81. doi: 10.1097/00000542-199107000-00013.
Halothane relaxes airway smooth muscles. To test the hypothesis that this relaxation is modulated by airway epithelium, we studied the effects of halothane on isolated second- and third-order canine bronchial rings and second-order canine bronchial segments. Paired rings or segments were examined, with the epithelium removed from one ring or segment of each pair. The bronchial rings were suspended in organ chambers and contracted with 10(-8)-10(-3) M acetylcholine (ACh), 10(-8)-10(-5) M 5-hydroxytryptamine (5HT), or 0.5-16 Hz electrical field stimulation (EFS, 15 V, 0.5-ms pulse duration). The tissue was contracted in the absence of halothane and during exposure to 1 and 2 MAC halothane. The bronchial segments were perfused intraluminally with physiologic salt solution (PSS) and contracted with 10(-6) M carbachol added to the tissue-bath PSS. One or 2 MAC halothane was then added to the perfusate. In the absence of halothane, epithelium removal increased the sensitivity of the bronchial rings to ACh and 5HT but not to EFS. Addition of 1 or 2 MAC halothane to the bathing fluid of the rings with or without epithelium decreased the sensitivity of the rings to ACh and 5HT. One MAC halothane decreased the sensitivity of the rings with and without epithelium to EFS. The decrease in sensitivity caused by halothane was not significantly different in rings with or without epithelium for any method of stimulation. In the bronchial segments, relaxations evoked by 1 or 2 MAC were not different in segments with or without epithelium.(ABSTRACT TRUNCATED AT 250 WORDS)
氟烷可舒张气道平滑肌。为验证气道上皮调节这种舒张作用的假说，我们研究了氟烷对分离的犬第二级和第三级支气管环以及犬第二级支气管节段的作用。对成对的支气管环或节段进行检测，每组中的一个环或节段去除上皮。将支气管环悬挂于器官浴槽中，用10(-8)-10(-3)M乙酰胆碱（ACh）、10(-8)-10(-5)M 5-羟色胺（5HT）或0.5-16Hz电场刺激（EFS，15V，0.5ms脉冲持续时间）使其收缩。组织在无氟烷时以及暴露于1和2MAC氟烷期间均发生收缩。支气管节段经腔内灌注生理盐溶液（PSS），并通过向组织浴PSS中添加10(-6)M卡巴胆碱使其收缩。然后向灌注液中添加1或2MAC氟烷。在无氟烷时，去除上皮会增加支气管环对ACh和5HT的敏感性，但对EFS无影响。在有或无上皮的环的浴液中添加1或2MAC氟烷可降低环对ACh和5HT的敏感性。1MAC氟烷可降低有或无上皮的环对EFS的敏感性。对于任何刺激方法，氟烷引起的敏感性降低在有或无上皮的环中无显著差异。在支气管节段中，1或2MAC引起的舒张在有或无上皮的节段中无差异。（摘要截断于250字）
