Tomita Ryouichi, Fujisaki Shigeru
Department of Surgery, Nippon Dental University School of Dentistry at Tokyo, Japan.
Hepatogastroenterology. 2008 Jul-Aug;55(85):1360-4.
BACKGROUND/AIMS: The cause of dysmotility in the small intestine of patients with small bowel transplantation (SBT) is still unknown. It is established that neurotensin (NT) is released by stimulation of non-adrenergic non-cholinergic (NANC) excitatory nerves. It is considered that the ileum is more important than the jejunum in regard to digestive functions. In order to evaluate the intestinal function of rat ileal isografts, this study examined the enteric nerve responses to electrical field stimulation (EFS) and NT in the isografted rat ileum, using the normal ileum as a control.
Orthotopic entire small bowel transplantation (SBT) with portocaval drainage was performed from Lewis rats to Lewis rats. Grafted tissue specimens were obtained 130 days after SBT (n = 8). As controls, normal segments of the ileum were obtained from untransplanted Lewis rats (n = 20). A mechanograph was used to evaluate in vitro ileal responses to electrical field stimulation (EFS) of the adrenergic and cholinergic nerve before and after treatments with various autonomic nerve blockers and NT.
All ileal muscle strips used in the present studies responded to EFS before and after the blockade of both the adrenergic and cholinergic nerves. The intrinsic innervation contains both excitatory (cholinergic and NANC excitatory nerves) and inhibitory nerves (adrenergic and NANC inhibitory nerves) in the normal and isografted ileum of LEW rats. Excitatory nerves, especially NANC excitatory nerves, were more dominant in the isografted ileum than in the normal ileum (P < 0.001). NANC inhibitory nerves were found to act on the normal ileum and to a greater extent in the isografted ileum (P < 0.05). NT mediates the contraction reaction of NANC excitatory nerve in the normal ileum and to a greater extent in the isografted ileum (P < 0.05).
Contraction reactions of NT were observed in both the normal and isografted ileum, but were increased in the isografted ileum. The increase of the NT in mediating NANC excitatory nerves and decrease of the NANC inhibitory nerves may be largely related to the peristaltic abnormalities seen in the isografted LEW rat ileum.
背景/目的：小肠移植（SBT）患者小肠运动障碍的原因尚不清楚。已知神经降压素（NT）由非肾上腺素能非胆碱能（NANC）兴奋性神经的刺激释放。就消化功能而言，回肠被认为比空肠更重要。为了评估大鼠回肠同种异体移植的肠道功能，本研究以正常回肠为对照，检测了同种异体移植大鼠回肠对电场刺激（EFS）和NT的肠神经反应。
将Lewis大鼠的原位全小肠移植（SBT）并进行门腔分流，受体为Lewis大鼠。在SBT术后130天获取移植组织标本（n = 8）。作为对照，从未移植的Lewis大鼠获取正常回肠段（n = 20）。使用肌动描记器评估在应用各种自主神经阻滞剂和NT处理前后，离体回肠对肾上腺素能和胆碱能神经的电场刺激（EFS）的反应。
本研究中使用的所有回肠肌条在肾上腺素能和胆碱能神经阻断前后均对EFS有反应。在LEW大鼠的正常和同种异体移植回肠中，内在神经支配包含兴奋性（胆碱能和NANC兴奋性神经）和抑制性神经（肾上腺素能和NANC抑制性神经）。兴奋性神经，尤其是NANC兴奋性神经，在同种异体移植回肠中比在正常回肠中更占优势（P < 0.001）。发现NANC抑制性神经作用于正常回肠，在同种异体移植回肠中的作用程度更大（P < 0.05）。NT介导正常回肠中NANC兴奋性神经的收缩反应，在同种异体移植回肠中的作用程度更大（P < 0.05）。
在正常和同种异体移植回肠中均观察到NT的收缩反应，但在同种异体移植回肠中增强。NT介导NANC兴奋性神经作用的增强和NANC抑制性神经作用的减弱可能在很大程度上与同种异体移植LEW大鼠回肠中所见的蠕动异常有关。
