钙离子在大鼠结肠平滑肌运动中作用机制的研究

目的 应用束缚应激大鼠实验模型，研究离体结肠平滑肌的收缩运动及其影响因素，探讨鸟苷素在结肠运动中的作用。方法 建立束缚应激大鼠动物模型，制备离体结肠平滑肌环行肌及纵行肌肌条，应用张力换能器，测定其肌张力。应用放射配基法测定结肠组织及血浆中鸟苷素含量。结果 束缚应激刺激可诱发大鼠排便增加，该动物模型是较好的模拟人ＩＢＳ的实验动物模型。束缚应激大鼠离体结肠平滑肌的张力升高，对Ｋ＾＋、Ｃａ＾２＋、乙酰胆

The regulation of calcium in the movement of colonic smooth muscle in wrap restraint stress rats

OBJECTIVE: To investigate the influence of contraction of isolated colonic smooth muscle and role of guanylin in colonic movement in wrap restraint stress rats. METHODS: By using wrap restraint stress induced defecation rats, the tone of isolated longitudinal and circular colonic muscle strips and guanylin contents in colon and blood were measured by transducer and radioligand binding assay respectively. RESULTS: There were similarities between the intestinal effects of wrap restraint stress in rats and irritable bowel syndrome (IBS) in human. Therefore, wrap restraint stress rat is an appropriate animal model to study stress related intestinal dysfunction. In wrap restraint stress rats, both the tone of smooth muscle and the reaction to K(+), Ca(2+) and acetycholine increased significantly; meanwhile guanylin contents in blood and colon increased also. Trimebutine can decrease the basic tone of smooth muscle and reaction to Ca(2+), K(+) and acetycholine. CONCLUSIONS: The abnormality of colonic smooth muscle contraction is one of the mechanisms in IBS and regulation of colonic smooth muscle contraction is a new method to treat IBS.