下丘脑外侧区微量注射胃动素对大鼠十二指肠消化间期复合肌电活动的影响

目的探讨下丘脑外侧区(LHA)微量注射胃动素对十二指肠消化间期复合肌电活动(IMC)的影响及其机制。方法采用中枢立体定位LHA微量注射的方法,观察静脉给予阿托品(50μg/kg)、酚妥拉明(200μg/kg)、普萘洛尔(100μg/kg)及抗胃动素血清(1∶50)和膈下迷走神经切断后,LHA微量注入胃动素(0.37 nmol)对十二指肠IMC的影响。结果LHA微量注入胃动素可以使十二指肠IMC周期明显变短,峰电振幅增加,峰电频率增快,但对峰电时相无明显影响;膈下迷走神经切断可完全阻断LHA微量注射胃动素对十二指肠IMC的影响;阿托品、酚妥拉明、普萘洛尔不能阻断LHA微量注射胃动素对十二指肠IMC的影响;抗胃动素血清只能部分阻断LHA微量注射胃动素对十二指肠IMC的影响。结论LHA外源性胃动素可改变十二指肠IMC的特征并在其调节中发挥着重要作用。

Effects of motilin in the lateral hypothalamus area on the interdigestive migrating myoelectrical complex in the rat

Objective To explore the effects of motilin in the lateral hypothalamus area(LHA) on the interdigestive myoelectrical complex(IMC) in rats.Methods Adult SD rats of either sex were used.A 24-gauge stainless steel guide cannula was stereotaxically implanted into the LHA through stereotaxic frame and silver electrodes were put into the duodenal muscularis serosa.0.37nmol motilin was injected into the LHA of conscious rats via the guide cannula.Then,the silver electrodes were connected with a RM6240B multilead physiological recording system to record the IMC.Results After motilin was injected into the LHA,the duodenal IMC cycle duration was decreased significantly.However,the amplitude of phase Ⅲ and the frequency of phase Ⅲ was increased,but there were no effects on the duration of phase Ⅲ.Effects of motilin in the LHA on IMC were completely abolished by subdiaphragmal vagotomy.Effects of motilin in the LHA on IMC were unaffected by intravenously injected atropine,phentolamine or propranolol.The anti-motilin serum partly abolished effects of motilin in the LHA on IMC.Conclusion Motilin in the LHA has effects on the duodenal IMC and plays an important role in its modulation.