生长抑素类似物对Oddi括约肌肌电活动的双向调节作用及其临床意义

Effect of sandostatin on myoelectic activities of SO and its clinical significance

目的探讨生长激素类似物善得定（sandostatin SS）对Oddi括约肌（Sphincter of oddi，SO）肌电活动的双向调节作用及其临床意义。方法40只空腹18h成年健康家兔随机分为5组，即静脉注射生理盐水组；皮下注射生理盐水组；小剂量静脉滴注SS组；大剂量皮下注射SS组；静脉注射654—2后小剂量静脉滴注SS组。两对钩状双极金属电极分别置于乳头及十二指肠浆膜下，使用RM6240多道生理仪及信号采集处理系统，实验在PBG-1型生理实验屏蔽柜内进行。连续记录SO肌电活动120～150min。结果对照第一、第二组用药前后SO肌电活动无明显变化，仍表现为单发、规律的SO锋电位（spike potentials of SO，sPs0）；小剂量静脉滴注SS组给药后2～3min出现规律、间断的SO肌电簇（myoelectronic activity of SO，MASO）；大剂量皮下注射SS组给药后2～3min，SO肌电活动消失，进入抑制状态；静脉注射6542后小剂量静脉滴注SS，SPSO和MASO均不复出现。结论高浓度的SS可以抑制SO肌电活动，导致SO处于舒张状态；而低浓度维持剂量的SS可以使SO肌电活动处于兴奋状态，导致SO蠕动加快；阻断乙酰胆碱能神经可以消除SS对SO肌电活动的兴奋作用。

Objective To study the effect of sandostatin on the myoelectic activities of SO. Methods Forty adult rabbits that had been fasting for 18 hours were divided into five groups with 8 in each. The first group was a control group with each instilled saline incessantly through the vein. The second group was the other control group, each member of which was injected with saline subcutane ously. The third group was instilled with sandostatin i.v. incessantly （0. 1 mg SS in 100 ml 5% sa line, 15 drops per min）. The fourth group was injected subcutaneously with sandostatin at a concentration of 0.1 mg in lml normal saline. Two couples of double claw metal electrode were put into layer under the chorion of sphincter and duodenum. The myoelectric signal was recorded with RM6240 multi-channel physiologic recording and signal processing system. Animals were restrained in PBG-1 physiological experiment shield cabinet and non-stop recording was conducted for 120- 150 min. Results 1） No notable changes were found in the two control groups before or after the administration of saline. 2） Regular and discontinuous MASO were observed 2-3 min after SS was given in the third group. 3） The single and regular SPSO disappeared in 2-3 min after the rabbits in the fourth group were injected with SS. 4） After 654-2 was instilled i. v, regular and discontinuous SPSO and MASO disappeared, although SS was given in the same way as the third group. Conclusion High concentration of SS could inhibit normal myoelectric activities of SO to result in the relaxant state while low concentration of SS could excite myoelectric activities of SO thereby to stimulate the peristalsis of SO. Blocked cholinergic nerve can dismiss the periaqueductal gray stimulation of SO with SS.