胆囊收缩素对豚鼠近端结肠平滑肌的作用及其机制  

The effect of cholecystokinin on proximal colon myocyte in guinea-pigs and its mechanism

作　　者：陈玲[1] 罗和生[1] 祝捷[1] 谭韡[1] 

机构地区：[1]武汉大学人民医院消化科,430060

出　　处：《中华消化杂志》2011年第3期178-181,共4页Chinese Journal of Digestion

基　　金：国家自然科学基金资助项目（30871148）

摘　　要：目的 通过记录胆囊收缩素（CCK）对近端结肠平滑肌条和平滑肌细胞膜离子通道电流的影响,研究其对结肠动力的影响及其在肠易激综合征（IBS）发病中可能存在的病理机制.方法 成年豚鼠（200～250 g）实验前禁食12 h,不禁水.处死动物取近端结肠约6 cm,记录离体近端结肠肌条在浓度为1×10-7、5×10-7、1×10-6mol/L的胆囊收缩素八肽（CCK-8）作用下的张力和收缩频率变化;用EPC-10膜片钳和图像分析软件系统检测1×10-7、5×10-7、1×10-6 mol/L CCK-8及经尼非地平预处理的1×10-6mol/L CCK-8对近端结肠平滑肌细胞钙依赖钾通道电流（1BKca）的影响.结果 结肠平滑肌肌条实验中,分别加入1×10-7、5×10-7、1×10-6mol/L CCK-8后正常的收缩活动明显增强,与加药前[（0.68±0.12）g]相比,收缩幅度分别增加（15.0±1.5）%、（28.0±1.4）%和（36.0±1.6）%（n=7,P值分别=0.023、0.005和0.001）,但频率变化不明显.膜片钳实验中,当越阶刺激为＋60 mV时加入1×10-7、5×10-7、1×10-6mol/LCCK-8,此时IBKCa电流分别为对照组的（117.45±3.60）%、（125.42±5.30）%和（136.98±6.80）%（n=7,P值均＜0.01）.预先加入尼非地平后,1×10-6mol/L CCK-8组＋60 mV时IBKca为对照组的（102.23±5.60）%（n=7,P=1.491）.结论 CCK通过促进Ca2＋内流,增加Ibkca,进而增强结肠平滑肌的运动,主要表现为收缩幅度的加快.Objective To investigate the effect of cholecystokinin （CCK） on colon motility and its mechanism in development of irritable bowel syndrome via recording ionic channels currents and contraction of guinea-pig proximal colon. Methods The guinea-pigs （body weight ranged from 200 g to 250 g） were deprived of food, but not water, for 12 hours before experiment. The animal was sacrificed and 6 cm of proximal colon was obtained. The contractile activity of isolated proximal colon in 1 × 10-7 ,5 × 10-7 or 1 × 10-6 mol/L of CCK-8 solution was recorded. The impact of 1 × 10-7 , 5 × 10-7 and 1 × 10-6 mol/L of CCK-8 and 1 × 10-6 mol/L CCK-8 nifidipin on current of calcium activated potassium channel （IBKac） was detected with an EPC-10 amplifier and an image analysis software.Results In comparison with blank [（0. 68 ±0. 12） g], the amplitude of colon contraction in 1 × 10-7 ,5×10-7 and 1×10-6 mol/L of CCK-8 was increased by （15. 0±1.5）%,（28. 0±1.4）%, and （36.0±1.6） %, respectively （ n = 7, P = 0. 023,0. 005 and 0. 01 ）, but there was no significant change of frequency. When exogenous stimulation at ＋60 mV, the current of IBKac was enhanced to （117. 45 ± 3.60）%, （125.42± 5. 30）% or （136. 98±6. 80）% in 10-7 ,5 × 10-7 or 10-6 mol/L of CCK-8,respectively, compared with controls （n= 7, P＜0.01 ）. However, after adding nifidipin, the current of IBKca was reduced to （102.23±5.60）% in 10-6mol/L of CCK-8 at ＋60 mV when compared with controls （n=7, P= 1. 491 ）. Conclusion CCK enhances proximal colonic motility by increasing Ca2＋ influx and IBKac current, which is characterized by enhancement of amplitude of contraction.

关 键 词：胆囊收缩素 钙依赖钾通道 结肠 

分 类 号：R285.5[医药卫生—中药学]