A型肉毒毒素对大鼠胃动力作用的研究

Studies on the effect of botulin-A on gastric motility and its mechanism in rat

目的探讨A型肉毒毒素(BTA)对大鼠胃动力的作用及其机制。方法选用雄性Wistar大鼠40只,随机分为4组,对照组,BTA10U(小剂量)组、20U(中剂量)组、40U(大剂量)组。给药方法均为剖腹胃窦部肌层注射,观察12周,记录进食量及体重变化。12周末,测定胃半排空时间以评价BTA对胃动力的影响,再用免疫组化法测定胃窦部乙酰胆碱酯酶(AchE)的表达。结果①中、大剂量组大鼠进食量及体重较对照组明显减低(P<0.05);小剂量组进食量及体重在短时间内与对照组比较差别显著(P<0.05)。②12周末,小剂量组胃半排时间110.5±26.67min长于对照组86.83±22.98min,但差异无统计学意义(P>0.05);中剂量组(161.67±23.53min)和大剂量组(200.33±44.37min)与对照组比较差异显著(P<0.05)。③AChE在胃窦部肌间神经丛表达的IOD值分别为:中剂量组(72.44±18.43)、大剂量组(68.38±10.60),显著低于对照组(98.05±16.53),差别有统计学意义(P<0.05)。结论BTA通过抑制胆碱能神经末梢Ach的释放,引起胃动力降低,胃排空减慢,致大鼠进食减少,体重减轻。

Objective To investigate the effect of botulin-A on the gastric motility and its mechanistu Methods Male Wistar rats of nine weeks old（n=40） were divided into four groups： small dose group, medium dose group, large dose group and control group. Laparotomy was done and BTA solution 0. 4ml or saline 0. 4ml was injected into the antrum. During the following twelve weeks, weight and diet of every rat in four groups were registered. At the end of the twelfth week, gastric semi-empty time （rain） was determined by nuclide scan, and the content of AChE in antrum was assessed by immunohistochemistry method. Results Diet intake and body weight of rats were significantly lower in middle and large dose groups than those in control group （P〈0. 05）. But in only a short time diet intake and body weight were significantly lower in small dose group than those in control group （P〈0. 05）. At the end twelve weeks, gastric semiempty time in small dose group was 110. 5±26. 67 rain, which was longer than that of control group （86.83±2.98 min ）, but there was no statiscally significant difference （P〉0. 05）. The gastric semi-empoty time in middle dose group （161.67±23. 53 min） and large dose group （200.33±44.37 min） was significantly longer than that of control group （86. 83± 22. 98 min） （P〈0.05）. IOD of AChE positive staining in antrum myenterie plexus in middle dose group （72.44±18. 43） and in large dose group （68. 38±10. 60） were mueh lower than those in control group （98. 05±16.53） （P〈0. 05）. Conclusions In jeetion BTA into the antrum smooth musele in rats can inhibit the release of Ach from cholinergie nervous system, decrease gastric motility, and restrict gastric emptying, cut down dietary intake and induce weight loss.