突触在胃起搏调控胃慢波活动中的作用

目的研究胃窦肌间神经丛中突触素（synaptophysin,Syn）分布及其mRNA和蛋白的表达,探讨突触素在胃起搏机制中的作用。方法通过手术建立Wistar大鼠胃起搏模型（近远端胃各缝制一对电极）,分为起搏组（GES组,n=10）和对照组（n=6）。应用免疫组化染色观察GES组和对照组胃窦间神经丛中突触素分布,采用逆转录聚合酶链反应（RT-PCR）和Western blot分别检测GES和对照组胃窦肌间神经丛中Syn mRNA和蛋白的表达量,以恒定表达的β-actin作为内参照。分别计算Syn mRNA与β-actinmRNA、Syn蛋白与β-actin蛋白表达积分光密度值的比值（Syn/β-actin）,以反映组织中Syn mRNA和蛋白的相对表达量。结果与对照组相比,GES组肌间神经丛中Syn免疫反应阳性产物分布显著增多（806.421±342.135vs448.3±261.467,P〈0.05;0.019±0.008vs0.010±0.005,P〈0.05）。RT-PCR研究显示GES组Syn mRNA表达显著强于对照组,GES组syn/β-actin比值明显较对照组增加（0.146±0.0 28vs0.082±0.025,P〈0.05）;Western blot研究显示GES组Syn蛋白表达也较对照组明显增强,两组Syn/β-actin比值比较差异有统计学意义（0.502±0.098vs0.298±0.018,P〈0.05）。结论胃起搏后胃肌间神经丛内突触素分布增多,突触素mRNA和蛋白表达量明显增加,表明胃窦肌间神经丛内突触可能在胃起搏中发挥了重要作用。

Role of synapses in gastric pacing-induced entrainment of gastric slow waves in rats

Objective To explore the role of synapses in gastric pacing-induced entrainment of gastric slow waves(GSWs) in rats.Methods The Wistar rat models with two pairs of electrodes were established by operation and divided into two groups,including the pacing group(GES,n=10) and control group(n=6).Using immunohistochemistry,synaptophysin(Syn) expression were measured in the antral myenteric plexus in GES group and control by RT-PCR and Western blot analysis.β-actin,a steadily expressed gene,was used as the internal reference.The ratios of Syn mRNA,Syn protein to β-actin mRNA,β-actin protein in the integrated optical density were calculated to represent the relative expression of Syn mRNA and Syn protein in the tissues.Results Syn immunoreactivity in the antral myenteric plexus in GES group was more abundant than that in control group(806.421±342.135 vs 448.3±261.467,P<0.05;0.019±0.008 vs 0.010±0.005,P<0.05);in the antral myenteric plexus,the expression of Syn mRNA and protein increased significantly in GES group compared with control group(0.082±0.025 vs 0.146±0.0 28;0.298±0.018 vs 0.502±0.098,P<0.05,respectively).Conclusion The synapses maybe play important roles in the mechanisms of gastric electrical pacing.