A型肉毒毒素抑制大鼠胃平滑肌收缩的放射免疫测定

目的:在胃肌层注射A型肉毒毒素(botulinumtoxintypeA,BTX-A)后,P物质(substanceP,SP)是否参与BTX-A抑制胃平滑肌收缩调节,尤其是局部短期变化,并探讨BTX-A的作用与SP的关系,为临床疗效提供新思路。方法:健康雄性Wistar大鼠14只,随机分为BTX-A组及对照组,在胃体前壁与幽门部交界线中点平滑肌内注射BTX-A5U(25U/ml),或者生理盐水0.2ml;注射3min后切取局部前壁组织行放射免疫测定。结果:胃前壁注射区局限性膨出,逐渐加剧;未见蠕动波/收缩波通过局部。从切取待测的胃前壁侧面观:厚度与周围比较无明显界限,但皱襞减少、变浅。BTX-A组SP平均含量较对照组低39%(P<0.05)。结论:经腹腔在胃前壁注射BTX-A后,不但阻碍了局部粘膜下神经丛或者肌间神经丛突触前膜乙酰胆碱释放,而且也抑制了SP,导致胃平滑肌收缩功能障碍。

Inhibited stomachic smooth muscle f ollowing local botulinum toxin type A injection in rats with radioimmunoassay method

AIM:The study investigated that botulin um toxin type A(BTX-A)injection into the stomach caused the changes o f substance P (SP)contents with ra-dioimmunoassay method in rats.METHODS:Rats were undergone either BTX-A(5U,25U /ml )injection into the smooth muscle lay er of gastric an-terior surface as BTX-A group(n=7)or sodium chloride(0.2ml,9g /L)as control one.RESULTS:The mean percentage of SP contents of control group versus BTX-A one decreased 39%at the3rd minute after treatment.CON-CLUSION:BTX-A injection at the smooth muscle leads to significant reduc-tion in contents of SP.BTX-A may inhi bit not only acetylcholine release i n the cholinergic nerve terminals but als o SP release on the autonomic them fro m myenteric ganglionated plexus and s ubmucosal ganglianated plexus.