Murakuni H
Second department of Surgery, Toho University School of Medicine, Tokyo, Japan.
J Smooth Muscle Res. 1994 Jun;30(3):111-24. doi: 10.1540/jsmr.30.111.
Our objective was to study the mechanism of action of gastrin and histamin H2 receptor antagonist on the motility of the gastrointestinal area. In each of 12 mongrel dogs, eight bipolar electromyograms were obtained from the antrum of the stomach to the ileum on serosal surface, and in nine dogs undergoing that the small intestine was transected 20 cm from the ligament of Treitz. The effects of tetragastrin (1.0-10.0 microgram.kg-1.h-1) were studied against the presence of atropine, cimetidine and d-chlorpheniramine maleate. The frequency of electrical control activity (ECA) along the canine small intestine, and changes in ECAs frequency were studied normal and following upper small intestinal transection. In intact, the frequency of ECAs gradient decreased aborally in a stepwise fashion in normal intestine. Although the gradient was markedly reduced or even abolished distal to the level of transection, an intrinsic ECAs frequency gradient was demonstrated, it remained at a low level indefinitely. The normal ECA pattern and its alterations following transection were significantly influenced by tetragastrin. The act of tetragastrin in a dose of 1.0 to 5.0 microgram.kg-1.h-1 had not statistically effect on ECAs frequency and its dysrhythmias, and it did cause a small increase in the frequency of ECA at the antrum, whereas, with the highest dose (10.0 microgram.kg-1.h-1) of used, the increase of mean frequency of ECA in the distal portion to the line of transection, in particular, was significantly greater compared to the change in the proximal portion. It was only cimetidine (8.0 mg.kg-1) that antagonized this action of tetragastin (10.0 microgram.kg-1.h-1). Histamine H2 receptors are suspected of being associated with the action the gastrin has of enhancing ECAs frequency. The results of this study indicate that histamine H2 receptors regularize gastrointestinal ECAs frequency.
我们的目的是研究胃泌素和组胺H2受体拮抗剂对胃肠道运动的作用机制。在12只杂种狗中，从胃窦到回肠的浆膜表面获取8个双极肌电图，其中9只狗的小肠在距屈氏韧带20厘米处被横断。研究了四肽胃泌素（1.0 - 10.0微克·千克⁻¹·小时⁻¹）在阿托品、西咪替丁和马来酸氯苯那敏存在时的作用。研究了犬小肠电控制活动（ECA）的频率以及正常情况下和上段小肠横断后ECA频率的变化。在完整状态下，正常肠内ECA频率梯度向口端呈阶梯状下降。虽然在横断水平远端梯度明显降低甚至消失，但仍显示出内在的ECA频率梯度，且该梯度会无限期保持在低水平。正常的ECA模式及其横断后的改变受到四肽胃泌素的显著影响。剂量为1.0至5.0微克·千克⁻¹·小时⁻¹的四肽胃泌素对ECA频率及其心律失常无统计学作用，但确实使胃窦处的ECA频率略有增加，然而，使用最高剂量（10.0微克·千克⁻¹·小时⁻¹）时，与近端部分的变化相比，横断线远端部分的ECA平均频率增加尤为显著。只有西咪替丁（8.0毫克·千克⁻¹）能拮抗四肽胃泌素（10.0微克·千克⁻¹·小时⁻¹）的这种作用。怀疑组胺H2受体与胃泌素增强ECA频率的作用有关。本研究结果表明组胺H2受体可调节胃肠道ECA频率。
