【摘要】 目的探讨在慢性心力应激大鼠模型中,机械刺激诱导的远端结肠黏膜离子转运是否发生改变。方法 SD大鼠分为对照组和模型组,采用束缚制动法制备慢性心理应激大鼠模型,通过排便测定、蔗糖水偏嗜度和悬尾实验测定其行为学,采用短路电流技术结合去除溶液中阴离子和运用各种阻断剂的方法,观察机械刺激诱导的远端结肠黏膜离子转运。结果同对照组比较,模型组大鼠的排便数量显著增加(P<0.05),蔗糖水偏嗜度显著降低(P<0.05),静止时间显著延长(P<0.05),而挣扎次数显著降低(P<0.05)。两组大鼠结肠黏膜的基础电生理特性无显著差异。机械刺激导致对照组和模型组大鼠结肠黏膜的短路电流均显著增加,但是模型组中增加的短路电流(△Isc)显著高于对照组(P<0.05)。去除溶液中的HCO-3并不能改变两组的△Isc,但是去除溶液中的Cl-均显著降低两组的△Isc(P<0.001)。运用Ca2+激活的Cl-通道(Ca2+-activated Cl-channel,CaCC)的阻断剂DIDS并不能改变两组的△Isc,但是运用囊性纤维变性跨膜电导调节器(cystic fibrosis transmembrane conductance regulator,CFTR)的抑制剂CFTR(inh)-172或Na+-K+-2Cl-共转运体(Na+-K+-2Cl-cotransporter,NKCC)的阻断剂bumetanide均显著降低两组的△Isc(P<0.001)。结论在慢性心理应激大鼠模型中,机械刺激诱导的远端结肠黏膜Cl-分泌增加,而这可能是功能性胃肠病(FGIDs)患者产生腹泻的原因之一。更多还原

【Abstract】 Objective To investigate whether the mechanical stimulus-induced ions transport in distal colon of chronic psychological stress rat model was altered. Methods SD rats were divided into control group and model group randomly. The rats in model group were exposed to bondage immobilization for 6 hours per day. The model rats were tested by feces granules counting,sucrose consumption test and tail-suspension test. The mechanical stimulus-induced ions transport in rat distal colon were investigated by short circuit current technique combined with removal extracellular anions and application of different blockers. Results The amount of feces granules,sucrose consumption and immobility duration in model group were increased significantly compared with control group( P < 0. 05),however,the struggle times were decreased significantly( P < 0. 05). Although there were no significant differences in electrophysiological properties between control group and model group,the mechanical stimulus-induced current( △Isc) in model group was statistically higher than that in control group( P < 0. 05). The △Isc in both control group and model group were reduced significantly by removal of extracellular Cl-( P <0. 001) but not HCO-3. The application of DIDS,a Ca2 +-activated Cl-channel blocker,didn’t alter the △Isc induced by mechanical stimulus in both groups. Howerer,addition of CFTR( inh)-172,the inhibitor of cystic fibrosis transmembrane conductance regulator,or bumetanide,a blocker of Na+-K+-2Cl-cotransporter,reduced the △Isc in control group and model group significantly( P < 0. 001). Conclusion The chronic psychological stress can increase mechanical stimulus-induced Cl-secretion in distal colon of rat,which is a possible mechanism responsible for the diarrhea of functional gastrointestinal disorders( FGIDs) patients.更多还原