Increased expression of insulin-like growth factor in intestinal lengthening by mechanical force in rats
Increased expression of insulin-like growth factor in intestinal lengthening by mechanical force in rats
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DOI：
10.1016/j.jpedsurg.2007.08.027
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发表时间：
2007-12-01
影响因子：
2.4
通讯作者：
Lee, Edward
中科院分区：
文献类型：
--
作者：
Dunn, James C. Y.;Lam, Mandy M.;Lee, Edward
简介：一段空肠可以通过施加轴向机械力使其长度增加一倍。我们假设这种生长与空肠中胰岛素样生长因子（IGF-I）表达的增加相关。方法：成年Sprague-Dawley大鼠分离1.5厘米的空肠段。分离的空肠段要么使用机械力延长或单独放置3周。通过定量聚合酶链反应和免疫荧光法对IGF-I表达的空肠段进行了分析。结果：虽然单独进行隔离的空肠段没有改变其长度，但通过施加逐渐的机械力拉伸的隔离空肠段使其初始长度增加了一倍。与正常空肠相比，两组的肌肉厚度均增加了5倍。延长空肠中IGF-I的mRNA水平是正常空肠的6倍，而未机械延长的离体空肠中IGF-I的mRNA水平无明显变化。免疫荧光显示，在延长的空肠中IGF-I的表达增加定位于肠平滑肌细胞。结论：胰岛素样生长因子I可能是轴向力诱导的一个重要信号，介导了肠的纵向生长。(c)2007年爱思唯尔公司All rights reserved.
Introduction: A segment of the jejunum could double its length by the application of an axial mechanical force. We hypothesize that this growth is correlated with an increased expression of insulin-like growth factor (IGF-I) in the jejunum.Methods: Adult Sprague-Dawley rats underwent the isolation of a 1.5-cm segment of the jejunum. The isolated jejunal segment was either lengthened using mechanical force or left alone for 3 weeks. The jejunal segments were analyzed by quantitative polymerase chain reaction and immunofluorescence for the expression of IGF-I.Results: Whereas jejunal segments that underwent isolation alone did not change their length, isolated jejunal segments that were stretched by applying a gradual mechanical force doubled their initial length. Both groups increased their muscular thickness 5 folds as compared to the normal jejunum. The mRNA level of IGF-I in the lengthened jejunum was 6 folds higher than that in the normal jejunum, but the IGF-I mRNA level in the isolated jejunum without mechanical lengthening was unchanged. By immunofluorescence, the increased IGF-I expression in the lengthened jejunum was localized to the intestinal smooth muscle cells.Conclusions: Insulin-like growth factor I may be an important signal induced by the applied axial force that mediates longitudinal intestinal growth. (c) 2007 Elsevier Inc. All rights reserved.