Duluc I, Galluser M, Raul F, Freund J N
Institut National de la Santé et de la Recherche Médicale, Unité 61, Strasbourg, France.
Am J Physiol. 1992 Jun;262(6 Pt 1):G954-61. doi: 10.1152/ajpgi.1992.262.6.G954.
At weaning, the lactase-phlorizin hydrolase (LPH) mRNA was shown to disappear specifically from the distal part of ileum while remaining abundant in the more proximal segments of the small intestine. The purpose of this study was to analyze the longitudinal distribution of this transcript in rats whose intestinal lumen content was modified before and after weaning. Preweaned animals force-fed with an artificial diet retained a high amount of LPH mRNA in the jejunum, whereas this transcript precociously decreased in the distal ileum. Conversely, prolonged nursing delayed the specific decay of the LPH mRNA in the latter segment. Food deprivation in preweaned animals did not alter the longitudinal distribution of this transcript in that it remained abundant in the distal ileum. In adult rats, rearranging the order of the small intestinal segments with regard to the intraluminal flow of nutrients did not modify the typical distribution of the LPH mRNA. These results suggest that switching over from milk to the adult-type diet at weaning contributes to the modification of the longitudinal distribution of the LPH mRNA that normally occurs at this stage. However, once the adult pattern of expression of this transcript is established, it cannot be significantly altered by changing the position of each intestinal segment as well as its luminal content.
在断奶时，乳糖酶 - 根皮苷水解酶（LPH）mRNA显示出从小肠远端部分特异性消失，而在小肠近端部分仍大量存在。本研究的目的是分析断奶前后肠腔内容物发生改变的大鼠中该转录本的纵向分布。断奶前人工喂养的动物空肠中保留了大量的LPH mRNA，而该转录本在回肠远端则过早减少。相反，延长哺乳时间会延迟后一段中LPH mRNA的特异性衰减。断奶前动物禁食并未改变该转录本的纵向分布，因为它在回肠远端仍大量存在。在成年大鼠中，改变小肠各段关于腔内营养物质流动的顺序并未改变LPH mRNA的典型分布。这些结果表明，断奶时从母乳过渡到成体类型饮食有助于改变LPH mRNA在此阶段正常发生的纵向分布。然而，一旦该转录本的成年表达模式建立，改变每个肠段的位置及其腔内内容物并不能显著改变它。
