Chung D H, Evers B M, Shimoda I, Townsend C M, Rajaraman S, Thompson J C
Department of Surgery, University of Texas Medical Branch, Galveston.
Gastroenterology. 1992 Oct;103(4):1254-9. doi: 10.1016/0016-5085(92)91512-3.
Neurotensin (NT) stimulates growth of normal and atrophic small bowel mucosa; the mechanisms for this trophic effect of NT are not completely known. The purpose of this study was to (a) determine whether the trophic effect of NT is mediated by mechanisms involving luminal or nonluminal factors and (b) determine whether NT exerts a differential trophic effect on either jejunal or ileal mucosa. Twenty-eight male Sprague-Dawley rats underwent construction of either a jejunal or ileal Thiry-Vella fistula (TVF). After a 1-week recovery period, rats were further subdivided into groups to receive either saline (control) or NT (300 micrograms/kg). Rats were killed on day 6, and TVF as well as corresponding segments of intact jejunum or ileum were removed. Mucosa was scraped, weighed, and analyzed for DNA and protein content. In addition, representative sections of full-thickness bowel from each group were examined histologically. In the jejunal TVF group, NT increased mucosal growth measurements in both the TVF and the intact jejunum. However, in the ileal TVF group, NT stimulated proliferation of intact ileal mucosa only; it had no effect on ileal mucosa in the TVF. These results suggest that NT exerts a systemic effect independent of luminal factors on the proliferation of proximal gut mucosa in addition to an indirect effect produced by stimulation of endogenous luminal secretions. In contrast, an indirect mechanism appears to be the predominant action of NT on growth of distal gut mucosa.
神经降压素（NT）可刺激正常和萎缩的小肠黏膜生长；NT这种营养作用的机制尚不完全清楚。本研究的目的是：（a）确定NT的营养作用是否由涉及肠腔或非肠腔因素的机制介导；（b）确定NT对空肠或回肠黏膜是否具有不同的营养作用。28只雄性Sprague-Dawley大鼠接受了空肠或回肠的Thiry-Vella瘘管（TVF）构建。经过1周的恢复期后，将大鼠进一步分为几组，分别接受生理盐水（对照组）或NT（300微克/千克）。在第6天处死大鼠，取出TVF以及完整空肠或回肠的相应节段。刮取黏膜，称重，并分析其DNA和蛋白质含量。此外，对每组全层肠管的代表性切片进行组织学检查。在空肠TVF组中，NT增加了TVF和完整空肠的黏膜生长指标。然而，在回肠TVF组中，NT仅刺激了完整回肠黏膜的增殖；对TVF中的回肠黏膜没有影响。这些结果表明，NT除了通过刺激内源性肠腔分泌物产生间接作用外，还对近端肠道黏膜的增殖发挥独立于肠腔因素的全身作用。相比之下，间接机制似乎是NT对远端肠道黏膜生长的主要作用方式。
