侧脑室微量注射ghrelin对大鼠小肠转运和肌电活动的影响及作用机制  

Effects of intracerebroventricular injection of ghrelin on small intestinal transit and myoelectric complex in rats

作　　者：王燕[1] 李路[1] 史海涛[1] 赵菊辉[1] 姜炅[1] 贾淼[1] 

机构地区：[1]西安交通大学医学院第二附属医院消化内科,西安710004

出　　处：《山西医科大学学报》2014年第10期911-915,共5页Journal of Shanxi Medical University

基　　金：国家自然科学基金资助项目(81100258)

摘　　要：目的探讨侧脑室微量注射ghrelin对大鼠小肠转运和小肠消化间期复合肌电活动(interdigestive myoelectric complex,IMC)的影响及作用机制。方法 1大鼠分别接受十二指肠导管置入及侧脑室套管置入,在禁食状态下经侧脑室给予ghrelin(0.4,1.6或6.4μg/kg),经十二指肠导管注入伊文氏蓝溶液,观察不同剂量ghrelin对禁食大鼠小肠转运的影响。另两组大鼠分别经侧脑室给予ghrelin受体拮抗剂(D-Lys3)GHRP-6(3.7μg/kg),(D-Lys3)GHRP-6(3.7μg/kg)+ghrelin(6.4μg/kg),探讨ghrelin的作用机制。2大鼠分别接受肠道电极置入及侧脑室套管置入,在禁食状态下采用多道生理记录仪监测消化间期MC,观察侧脑室微量注射ghrelin(6.4μg/kg)对大鼠小肠IMC的影响。经侧脑室给予(D-Lys3)GHRP-6(3.7μg/kg)和NPY抗体(4μg/kg),再经侧脑室给予ghrelin(6.4μg/kg);经静脉给予阿托品(1 mg/kg)、酚妥拉明(1 mg/kg)或普萘洛尔(1 mg/kg),再经侧脑室给予ghrelin(6.4μg/kg),观察侧脑室注射ghrelin对IMC影响的作用机制。结果 1侧脑室微量注射ghrelin 0.4μg/kg对大鼠小肠转运无显著影响,ghrelin 1.6μg/kg和6.4μg/kg促进小肠转运,此促进作用可被(D-Lys3)GHRP-6阻断。2侧脑室微量注射ghrelin促进十二指肠和空肠IMC,使IMC周期缩短,Ⅲ相频率和振幅增加,Ⅲ相时程缩短,对Ⅲ相占IMC周期百分比无显著性改变。阿托品和(D-Lys3)GHRP-6不同程度地抑制ghrelin的促动力效应;酚妥拉明和普萘洛尔对ghrelin的促动力作用无显著影响。结论侧脑室微量注射ghrelin可促进小肠运动,这可能是通过外周胆碱能通路起作用,ghrelin受体GHS-R参与其促动力作用。Objective To investigate the effects and mechanism of ghrelin on small intestinal transit and interdigestive myoelectrical complex（IMC） in rats. Methods ①Rats were pretreated with intraduodenal catheter and intracerebroventricular catheter implanta- tion. Some rats received intraeerebroventricular injection of ghrelin（0. 4, 1.6 or 6. 4μg/kg） in fasting state, respectively. The small intestinal transit was measured after instillation of Evans blue through the intraduodenal catheter. Other rats received ghrelin receptor antagonist （ D-Lys3 ） GHRP-6 in one group and （ D-Lys3 ） GHRP-6 ＋ ghrelin in another group to investigate the role of ghrelin. ②Mter receiving intestinal electrodes and intracerebroventricular catheter implantation, IMC was recorded by the muhilead physiological re- cording system during the fasting state before and after ghrelin intracerebroventricular injection. Atropine, phentolamine, propranolol and ghrelin receptor antagonist （D-Lys3） GHRP-6 were administrated after the injection of ghrelin to investigate the role of ghrelin on IMC. Results Ghrelin 0.4 μg/kg had little influence on small intestinal transit, however ghrelin 1.6 or 6. 4 μg/kg accelerated the small intestinal transit. This effect was inhibited by its receptor antagonist. The IMC cycle length and the duration of phase Ⅲ were shortened after ghrelin injection without affecting the percentage of phase Ⅲ in the IMC cycle. Atropine and （D-Lys3） GHRP-6 inhibi- ted the effects of ghrelin respectively, while phentolamine and propranolol had little effect on it. Conclusion Intracerebroventricular injection of ghrelin appears to have excitatory effects on the small intestinal motility, which rely on the cholinergic pathway. Its receptor GHS-R is involved in its activities.

关 键 词：GHRELIN 生长激素促分泌素受体 小肠转运 消化间期复合肌电活动 

分 类 号：R333.3[医药卫生—人体生理学]