内吗啡肽对泻剂结肠大鼠结肠肌电活动的影响

目的研究内吗啡肽对泻剂结肠大鼠结肠肌电活动的影响,探讨慢传输性便秘的发病机制。方法建立泻剂结肠动物模型,测定内吗啡肽1和内吗啡肽2对大鼠结肠肌电活动的影响。结果泻剂组大鼠结肠慢波频率和振幅分别为(28.19±7.51)次/min和(0.076±0.018)mV,与对照组比较(36.05±8.94次/min)和(0.600±0.310)mV]明显降低;内吗啡肽1、内吗啡肽2以浓度依赖方式抑制泻剂结肠的慢波肌电活动,振幅明显降低,频率(2 8.18±7.51)次/min3无明显变化,内吗啡肽1的作用强于内吗啡肽2。注射内吗啡肽不能阻断乙酰胆碱对结肠的兴奋作用。阿片受体拮抗剂纳洛酮(naloxone)能逆转内吗啡肽的抑制作用。结论内吗啡肽参与了泻剂结肠大鼠结肠肌电活动和结肠动力的调控,可能是慢传输性便秘发病的重要因素之一。

Effect of endomorphin on colonic electromyography activity in endomorphin cathartic colon rats

Objective To determine the effect of endomorphin (EM) on colonic electromyography activity and investigate the pathogenesis of slow transit constipation (STC). Methods An experimental rat model of slow transit constipation was constructed by contract laxatives mixed with the feed. The changes of colonic electromyography and reaction to endomorphin 1 and endomorphin 2 were examined. Results Compared with the control group, the frequency and amplitude of slow wave in cathartic colon rats were decreased significantly. Endomorphin 1 and endomorphin 2 significantly decreased the amplitudes of slow wave, but did not change the frequencies of slow wave. The effect of endomorphin 1 was more pronounced than that of endomorphin 2, which could be reversed by the morphine antagonist Naloxone in concentration-dependent manner. Endomorphin could not block the stimulating effect of acetylcholine. Conclusions Endomorphin can influence the colonic electromyography activity and intestine motility of cathartic colon rats, and may be involved in the pathologic mechanism of slow transit constipation.