摘要
目的观察异丙酚对延髓基本呼吸中枢吸气呼吸神经元放电活动的作用规律及其可能的作用机制.方法以改良的Kreb氏液灌流新生SD大鼠离体延髓脑片,随机分成Ⅰ～Ⅵ组(每组n=6).Ⅰ组为对照组(modified Kreb's solution,MKS组),第Ⅱ～Ⅴ组异丙酚浓度分别为5、20、50和100μmol/L持续灌流3 min,第Ⅵ组给γ-氨基丁酸A受体特异性阻断剂荷包牡丹碱(bicuculline,20μmol/L)与异丙酚20 μmol/L,观察给药后1、3、5、10、15、30 min时呼吸吸气神经元放电时程和峰值、呼气时程(吸气神经元放电静止期)和呼吸频率活动的变化.结果(1)第Ⅱ～Ⅴ组在1～30min内吸气神经元放电时程均表现为逐渐显著减小,15 min时作用最显著,且各组与MKS灌流的对照组相比均有显著性差异.(2)Ⅲ、第Ⅱ～Ⅴ组1min内呼气时程无显著性变化,3～30min内呼气时程均表现为显著延长,5～15min内达到其最大效应.(3)在给药后的30min内放电峰值呈现先增加然后降低的趋势,各组间放电峰值无显著性差异.(4)给予异丙酚3～30 min内呼吸频率逐渐减慢,5～15 min内达到其最大抑制效应,各组间呼吸频率的变化无显著性差异.(5)Ⅵ+Ⅳ组的吸气时程与间给药前比无显著性差异.结论(1)异丙酚可抑制新生大鼠离体延髓脑片标本吸气神经元的放电时程,主要表现为吸气时程的缩短和呼气时程延长,且呼吸呈浓度依赖性.(2)GABAA受体在异丙酚对延髓基本呼吸中枢呼吸气吸神经元放电活动的抑制作用中可能起重要作用.
Objective To investigate the effects of propofol on the electric discharge of the inspiratory neurons in the neonatal rat brainstem slices and its possible mechanism. Methods Experiments were performed on in vitro neonatal rat (of either sex, 0 to 30 d old) brainstem slices perfused with modified Kreb's solution (MKS), and the rhythmical discharge activity of the in-spirotory neurons in the hypoglossal nerve was recorded by suction electrode. Thirty-six slices positive of respiratory-related rhythmic activity were randomly divided into 6 equal groups consisting of a control group (groupⅠ) with MKS perfusion, 4 propofol groups (groups ⅡtoⅤ) with propofol treatment delivered via continuous MKS perfusion for 3 min at the doses of 5, 20, 50, 100 μmol/L respectively, and a bicuculline-propofol group (group Ⅵ) with the continuous perfusion of bicuculline (20 μmol/L) and propofol (20 μmol/L). The discharge time course of inspiratory, expiratory, peak inspiratory discharge and the frequency of respiration were recorded before and 1, 3, 5, 10, 15, 30 min after propofol or bicuculline-propofol perfusion. Re鄄sults In control group, no significant changes took place in all Hreparameters in the whole course of the experiment. In groupsⅡto Ⅳ, the discharge time was significantly reduced after propofol perfusion and at 5 min, and the discharge was arrested in 4 out of the 6 slices in group Ⅴ, showing a concentration-dependent inhibition of the inpiratory discharge time by propofol. In contrast, the expiratory time course was prolonged and frequency of respiration decreased in the period of 3 to 30 min after propofol perfusion. Combined treatment of bicuculine and propofol produced no significant changes in the discharge time and expiratory time courses of the inspiratory neurons. Conclusion Propofol inhibits the discharge of inspiratory neurons in a con-centration-dependent manner and GABA A receptor may play an important role in this process.
出处
《第一军医大学学报》
CSCD
北大核心
2003年第8期761-765,共5页
Journal of First Military Medical University
基金
国家自然科学基金(30170309)~~
