外源性胶质细胞源性神经营养因子对慢传输型便秘大鼠肠道传输功能的影响

背景：慢传输型便秘（STC）是一种以结肠动力障碍为主要特点的顽固性便秘，与肠神经系统功能紊乱密切相关。目的：探讨外源性胶质细胞源性神经营养因子（GDNF）对STC大鼠结肠组织中的GDNF表达及其肠道传输功能的影响。方法：以大黄灌胃建立STC大鼠模型。将大鼠随机分为正常对照组、GDNF对照组、STC模型组和模型GDNF组。GDNF对照组和模型GDNF组经尾静脉注射重组人GDNF，正常对照组和STC模型组经尾静脉注射0．9％NaCl溶液。1周后，以墨汁推进实验测定肠道传输功能，以免疫组化法检测结肠组织GDNF表达。结果：STC模型组肠道推进率与正常对照组和GDNF对照组相比显著降低（P〈0．叭）；模型GDNF组肠道推进率与STC模型组相比显著升高（P〈0．01），与正常对照组和GDNF对照组相比差异无统计学意义（P〉0．05）。STC模型组结肠组织GDNF阳性面积和积分光密度（IOD）值与正常对照组和GDNF对照组相比显著降低（P〈0．01）；模型GDNF组GDNF阳性面积和IOD值与STC模型组相比显著升高（P〈0．01），与正常对照组和GDNF对照组相比差异无统计学意义（P〉0．05）。结论：长期使用大黄会导致大鼠肠壁组织中的GDNF表达减少，而给予外源性GDNF可提高其表达，从而改善肠道传输功能。

Effect of Exogenous Glial Cell Line-derived Neurotrophic Factor on Intestinal Transit Function in Slow Transit Constipation Rats

Background： Slow transit constipation （STC） is mainly characterized by colonic motility disorder and has a close relationship with enteric nervous system alterations. Aims： To investigate the effect of exogenous glial cell line-derived neurotrophic factor （GDNF） on expression of GDNF in colonic tissue and intestinal transit function in STC rats. Methods： STC model was established by gastric infusion of rhubarb in rats. Rats were randomly divided into normal control group, GDNF control group, STC model group and model GDNF group. Rats in GDNF control group and model GDNF group were injected with recombinant human GDNF into caudal vein. Normal control group and STC model group were injected with same amount of 0.9% NaCl solution. One week later, the colonic transit function was measured by ink propulsion test, and the expression of GDNF in colonic tissue was determined by immunohistochemistry. Results： The intestinal propulsion rate in STC model group was significantly lower than that in normal control group and GDNF control group （ P 〈 0.01 ）. The intestinal propulsion rate in model GDNF group was significantly higher than that in STC model group （ P 〈 0.01 ） but similar to that in normal control group and GDNF control group （ P 〉 0.05 ）. The positive area and integrated optical density （IOD） value of GDNF in colonic tissue in STC model group were significantly lower than those in normal control group and GDNF control group （ P 〈 0.01 ）. The positive area and IOD value of GDNF in model GDNF group were significantly higher than those in STC model group （ P 〈 0.01 ） but similar to those in normal control group and GDNF control group （ P 〉 0. 05 ）. Conclusions ： Long term use of rhubarb can down-regulate the expression of GDNF in colonic tissue of rats. Exogenous GDNF may enhance the expression of GDNF and improve the intestinal transit function.