Fox-Threlkeld J A, McDonald T J, Cipris S, Woskowska Z, Daniel E E
School of Nursing, McMaster University, Hamilton, Ontario, Canada.
Gastroenterology. 1991 Dec;101(6):1471-6. doi: 10.1016/0016-5085(91)90381-t.
The role of porcine galanin, infused arterially into isolated perfused canine ileal segments, in modulating the tonically elevated neural release of vasoactive intestinal polypeptide and possible concomitant motor actions dependent on vasoactive intestinal polypeptide modulation was studied. Galanin infusions (9-minute) inhibited vasoactive intestinal polypeptide release in a concentration-dependent manner (maximum during minutes 8-10) irrespective of the absence (quiescence) or presence of phasic circular muscle contractions induced by local electrical field stimulation of nerves. During quiescence, galanin induced phasic contractions in four of five segments beginning in the 8th minute of the infusion. During stimulated contractions, galanin inhibited phasic motor activity within 2 minutes of initiation of the infusion; this inhibition may result from direct smooth previously reported muscle inhibition. Thus galanin may inhibit both neural release of vasoactive intestinal polypeptide and circular muscle motility directly. The delayed period of phasic activity initiated by galanin during quiescence may be related to inhibition of vasoactive intestinal polypeptide release, freeing the muscle from tonic inhibition by vasoactive intestinal polypeptide. Because galanin and vasoactive intestinal polypeptide are colocalized in some enteric nerves, galanin may regulate vasoactive intestinal polypeptide release by negative feedback.
研究了经动脉注入离体灌注犬回肠段的猪甘丙肽在调节血管活性肠肽持续升高的神经释放以及可能伴随的依赖于血管活性肠肽调节的运动作用中的作用。甘丙肽输注（9分钟）以浓度依赖性方式抑制血管活性肠肽释放（在第8 - 10分钟达到最大），无论是否存在由局部电场刺激神经引起的阶段性环行肌收缩（静止状态）。在静止状态下，甘丙肽在输注第8分钟开始时在五个节段中的四个节段诱导了阶段性收缩。在刺激收缩期间，甘丙肽在输注开始后2分钟内抑制了阶段性运动活动；这种抑制可能源于先前报道的直接平滑肌抑制。因此，甘丙肽可能直接抑制血管活性肠肽的神经释放和环行肌运动。甘丙肽在静止状态下引发的阶段性活动延迟期可能与血管活性肠肽释放的抑制有关，使肌肉从血管活性肠肽的紧张性抑制中解脱出来。由于甘丙肽和血管活性肠肽共定位于一些肠神经中，甘丙肽可能通过负反馈调节血管活性肠肽的释放。
