苯扎氯铵对大鼠结肠神经及平滑肌的影响

Effect of benzalkonium chloride on colonic nerve and smooth muscle of rat

目的研究苯扎氯铵对大鼠结肠神经及平滑肌的影响.方法 8～9周龄SD大鼠50只,随机分为两组.氯胺酮麻醉下开腹,实验组用0.1%苯扎氯铵处理大鼠降结肠浆膜40 min,温盐水冲洗后关腹,对照组用生理盐水代替苯扎氯铵.分别于术后1、2、3、4、8周取处理段结肠行组织学检查,反转录-聚合酶链反应(RT-PCR)检测乙酰胆碱酯酶(AchE)、巢蛋白(nestin)、乙酰胆碱M3受体(Chrm3)的表达,循环水浴药理学检测平滑肌收缩功能变化.结果苯扎氯铵处理后1周,大鼠结肠神经节细胞明显减少、空泡变,3周后完全消失;结肠平滑肌对乙酰胆碱敏感性增强.结论采用0.1%苯扎氯铵可使大鼠结肠产生去神经作用,结肠平滑肌对乙酰胆碱敏感性增强.

Objective To investigate the effect of benzalkonium chloride （BAC） on colonic nerve and smooth muscle of rat. Methods Fifty Sprague Dawley rats, 8-9 weeks old, were randomly divided into two groups：treatment group （n=25） and control group （n=25）. All animals were operated upon under ketamine anesthesia. In treatment group,0.1% benzalkonium chloride （BAC） was applied onto the serosa for 40 minutes, and then the colon was washed well with 0.9 % normal saline. For the control group, 0.9 % saline was applied using the same method as in treatment group, Microscopic observations, the expression of AchE, nestin, Chrm3 by RT-PCR and pharmacologic examinations for contraction of colonic smooth muscle were performed at an interval of 1 w, 2w, 3w, 4w and 8w after operation. Results Histologic examinations revealed obvious reduction and vacuolation of ganglion cells 1 week after BAC treatment, with a complete disappearence in 3 weeks after BAC treatment. Pharmacologic examinations indicated the colonic smooth muscle got an enhanced sensitivity to acetylcholine 1 week after BAC treatment. Conclusion The denervation of colon in rat can be produced by applying 0.1% benzalkonium chloride onto the serosa of colon, and the colonic smooth muscle becomes supersensitive to acetylcholine,