早期术后肠麻痹小鼠肠系膜传入神经电活动的变化

摘要

目的:通过观测早期术后肠麻痹小鼠肠系膜传入神经电活动的变化,探讨早期术后肠麻痹的发生机制.方法:C57BL/6小鼠通过经典小肠操作方法建立术后肠麻痹和假手术对照组的模型.术后3 h,进行离体细胞外多元肠系膜传入神经电活动的记录(n=6).结果:术后肠麻痹时小鼠离体小肠收缩的振幅明显减少(P＜0.05).假手术对照组浆膜外给予5-羟色胺(5-HT)刺激,肠系膜传入神经电位活动明显高于术后肠麻痹组;在低压力扩张(肠腔压力为10-20 mmHg和20-30 mmHg)时,假手术对照组小肠传入神经放电明显高于术后肠麻痹组.结论:早期术后肠麻痹时肠道运动明显受抑,小肠肠系膜传入神经对刺激的反应性降低,后者可能参与早期术后肠麻痹的发生发展.%AIM: To observe the changes of mesenteric afferent nerve discharge during the early phase of postoperative ileus ( POI ).METHODS: Under enflurane anesthesia, C57BL/6 mice underwent laparotomy followed by sham operation or standardized small bowel manipulation to induce POI.Three hours after operation, extracellular multi - unit mesenteric afferent nerve discharge was recorded ( n = 6 in each subgroup ).RESULTS: Amplitudes of intestinal contractions were ( 0.67 ± 0.03 ) mmHg after POI induction and ( 3.82 ± 0.54 ) mmHg in sham group ( P ＜ 0.05 ).The intestinal afferent firing in response to serosal 5 - hydroxytryptamine ( 5 - HT ) stimulation was followed by a decrease in the mesenteric afferent nerve discharge to(7.5±1.1) imp · s-1 in POI segments, compared with ( 20.5 ±5.5 ) imp · s-1 in sham group ( P ＜0.05 ).During intraluminal distension pressure from 10 to 20 mmHg and from 20 to 30 mmHg, the mesenteric afferent nerve discharges in POI segments were ( 30.8 ±6.6 ) imp · s-1 and ( 41.4 ±6.7 ) imp · s-1 , respectively, lower than those in sham group [( 40.6 ±5.5 ) imp · s-1 and ( 63.9 ±9.6 ) imp · s-1 , respectively, P ＜0.05].CONCLUSION : The mesenteric afferent nerve discharge in response to 5 - HT and low - threshold distension is reduced in the early phase of POI.