红霉素对兔消化间期胆囊运动的兴奋作用

Effects of erythromycin on the motility of gallbladder in the interdigestive period in rabbits

为研究红霉素（ＥＭ）对兔胆囊（ＧＢ）运动的影响，动物禁食后静脉麻醉，同步记录ＧＢ内压及奥迪氏括约肌（ＳＯ）肌电，静脉注射ＥＭ后ＧＢ运动增强，注药后１０ｓ内出现第１相效应（Ｐｈａｓｅ Ａ），表现为ＧＢ内压升高；注药后 １０ｍｉｎ开始出现第２相效应（Ｐｈａｓｅ Ｂ），主要是ＧＢ位相性收缩增强。 ＥＭ静脉灌注兴奋ＣＢ运动的效应同ＥＭ静脉注射相似。静脉注射阿托品或颈部迷走神经切断后静脉灌注或注射ＥＭ，ＰｈａｓｅＡ依然存在，而Ｐｈａｓｅ Ｂ消灭。结果提示， ＥＭ先后引起ＧＢ内压升高及ＧＢ位相性收缩增强两相效应，其中ＰｈａｓｅＡ可能是ＢＭ 直接兴奋胆道平滑肌上受体实现的，Ｐｈａｓｅ Ｂ是ＥＭ通过兴奋胆碱能神经通路起作用。

These experiments were designed to investigate the effects of erythromycin (EM) on the motility of gallbladder (GB). After fasted for about 15 - 18 hours but allowed to drink water, the rabbits were anesthetized with urethane (1.0g/kg, tv). Mean GB and myoelectric signals of sphincter of Oddi (SO) were recorded by polygraph. EM (10mg/kg, iv.) enhanced the motility of GB, and the effect was divided into two phases. The first phase (Phase A) began at 10 seconds and ended at 3 minutes after EM administration. At this phase, GB pressure increased. The second phase (Phase B) begin at 10 minutes and ended at 20 minutes after EM injection, and at this phase GB pressure did not change but the strength of phasic contraction of GB was enhanced significantly. Spike potentials of SO was also enhanced after EM injection. The effect of EM intravenous infusion (1 mg/kg·min, 20min ) on the motility of GB and SO was similar to that of EM intravenous injection (10mg/kg), Atropine (0.2mg/kg) or cervical vagotomy blocked the Phase B but did not affected the Phase A. Thus we concluded that, EM intravenous injection excited the motility of GB by raising GB pressure (Phase A) and enhancing the strength of phasic contraction of GB (Phase B). Phase A was mediated by receptor and Phase B was via neural cholinergic pathway.