el-Murr M, Kimura K, Ellsberg D, Yamazato M, Yoshino H, Soper R T
Department of Surgery, University of Iowa College of Medicine, Iowa City 52242.
Dig Dis Sci. 1994 Dec;39(12):2619-23. doi: 10.1007/BF02087699.
The isolated bowel segment (IBS) is an amesenteric segment of bowel that is devoid of extrinsic nerves and yet is viable with motility and absorption preserved after its mesentery is completely severed. The IBS is created by initial coaptation of a loop of bowel to a host organ, such as muscle (Iowa model I), liver (Iowa model II), or intestine, and secondary severance of its mesentery several weeks later. In previous studies using Iowa models I and II, the viability, motility, and absorption of the IBS were preserved by vascular collaterals, which form across the coaptation. In rats, an IBS was created in the jejunum by initial enteroenteropexy (Iowa model III), followed by its mesenteric division five weeks later. At the second laparotomy, bipolar electrodes were implanted in the IBS and the adjacent jejunum. One week later, myoelectrical recording was performed during a fasting state. Coordinated abroad propagation of migrating motor complex (MMC) was observed in the IBS. The MMC period was 16.9 +/- 1.7 and 19.3 +/- 0.8 min in the intact bowel, and 22.8 +/- 0.8 min in the IBS (P = 0.1). After feeding, the MMC in the IBS was replaced by irregular spike burst activity similar to that observed in the intact bowel. This study concludes that the IBS Iowa model III can be used for studies of bowel physiology.
孤立肠段（IBS）是一段无肠系膜的肠段，其缺乏外在神经，但在肠系膜完全切断后仍具有活力，且保留了蠕动和吸收功能。IBS是通过将一段肠袢最初与宿主器官（如肌肉，爱荷华模型I；肝脏，爱荷华模型II；或肠道）吻合，然后在数周后二次切断其肠系膜而形成的。在先前使用爱荷华模型I和II的研究中，IBS的活力、蠕动和吸收功能通过在吻合处形成的血管侧支得以保留。在大鼠中，通过最初的肠肠固定术（爱荷华模型III）在空肠中创建IBS，随后在五周后进行肠系膜分离。在第二次剖腹手术时，将双极电极植入IBS和相邻的空肠。一周后，在禁食状态下进行肌电记录。在IBS中观察到移行运动复合波（MMC）的协调广泛传播。完整肠段的MMC周期为16.9±1.7分钟和19.3±0.8分钟，IBS中的MMC周期为22.8±0.8分钟（P = 0.1）。进食后，IBS中的MMC被类似于完整肠段中观察到的不规则棘波爆发活动所取代。本研究得出结论，爱荷华模型III的IBS可用于肠道生理学研究。
