生长抑素对猕猴小肠环形肌收缩的影响及机制探讨  

Somatostatin Promotes Spontaneous Contractions of Small Intestinal Circular Muscle via Activation of Subtype 2 Somatostatin Receptors in Myenteric Nerve Plexus of Macaque Intestine

作　　者：李丹丹[1] 陈平[1] 郭梅梅[1] 唐承薇[1] 

机构地区：[1]四川大学华西医院生物治疗国家重点实验室人类多肽相关疾病研究室消化内科,成都610041

出　　处：《四川大学学报（医学版）》2010年第1期39-42,共4页Journal of Sichuan University(Medical Sciences)

基　　金：国家自然科学基金(批准号30330270)资助

摘　　要：目的探讨生长抑素(SST)对猕猴小肠环形肌自主收缩的直接作用及分子靶点。方法通过开腹手术获得成年猕猴的小肠环形肌条,应用张力换能器将信号输入生理记录仪,记录小肠环形肌条在不同SST浓度作用时的自主收缩幅度和频率;通过免疫组织化学方法观察SST在小肠组织内的分布,利用原位杂交检测SST受体2(SSTR2)的表达。结果SST低浓度组(1×10-7mol/L)小肠环形肌收缩频率〔(8.33±1.53)次/min〕较对照组明显增加〔(2.67±0.58次/min),P<0.05〕。在1×10-7mol/L～1×10-4mol/L SST浓度范围内,小肠环形肌收缩频率呈剂量依赖性提高(r=0.984,P<0.05);小肠环形肌收缩幅度仅在SST浓度(1×10-7mol/L～1×10-5mol/L)范围内呈剂量相关性增加(r=0.991,P<0.05)。在猕猴小肠纵行和环行肌间可见散在分布的SST及SSTR2的阳性神经丛,小肠平滑肌细胞上未见SSTR2。结论SST经小肠平滑肌间神经丛上的SSTR2介导,发挥对小肠环形肌自主收缩的兴奋作用。Objective To investigate the mechanism behind the inhibitive effect of somatostatin （SST） on the intestinal migrating contraction in vivo by observing the effect of SST on spontaneous contractions of the circular muscle of the isolated small intestine and visualizing SST and SST receptor 2 （SSTR2） in the intestinal muscle. Methods Transverse segments of macaque intestine from laparotomy, were mounted in a perfusion system. The effects of SST on their phasic contractions were recorded. SST and SSTR2 in the intestinal muscles of macaque were visualized by immunohistochemical staining and hybridization in situ. Results SST （1 ×10^-7 mol/L to 1 ×10^-4 mol/L） significantly increased the frequency of phasic contractions , in a dose-dependent manner, r=0. 984, P〈 0. 05 ; （8.33 ±1.53） times/rain （SST 1 ×10^-7mol/L） vs （2.67±0. 58） times/mitt （blank control）, P〈0. 05, The contractive amplitudes of the isolated circular muscle were also enhanced with the increasing concentration of SST range from 1 ×10^-7 mol/L to 1 ×10^-5 tool/L, r=0. 991, P〈0. 05. Both SST and SSTR2 were localized in myenterie nerve plexus between the longitudinal and the circular muscle of the macaque intestine. Conclusions SST directly promoted spontaneous contractions of the circular muscle of macaque intestine via mediation of SSTR2 in myenteric nerve plexus between the longitudinal and the circular muscle. It is contributed to the inhibitive effect of SST on the intestinal migrating contractions.

关 键 词：生长抑素 小肠 猕猴 自主收缩 

分 类 号：R965[医药卫生—药理学]