Freund J N, Duluc I, Raul F
Institut National de la Santé et de la Recherche Médicale, Unité 61, Strasbourg, France.
Gastroenterology. 1991 Feb;100(2):388-94. doi: 10.1016/0016-5085(91)90207-2.
This study shows the distribution of the messenger RNA for lactase-phlorizin hydrolase during postnatal development and along the longitudinal axis of the rat small intestine. At birth, this messenger RNA was present along the whole length of small intestine, and its concentration remained elevated during the suckling period despite the concomitant decrease in enzyme activity. At weaning, the amount of lactase messenger RNA dropped specifically in the distal ileum. This decrease in lactase messenger RNA was initiated at the ileocecal junction, progressed gradually towards the jejunum, and followed the decrease in lactase activity several days later. Starvation and refeeding were also found to cause modifications of lactase activity and messenger RNA expression that were prominent in the distal part of small intestine. These data support that posttranscriptional and pretranslational levels of regulation are required to define the spatial and temporal expression of lactase in the rat small intestine.
本研究显示了乳糖酶 - 根皮苷水解酶信使核糖核酸在大鼠出生后发育过程中以及沿小肠纵轴的分布情况。出生时，这种信使核糖核酸存在于小肠的全长，尽管酶活性随之下降，但在哺乳期间其浓度仍保持升高。断奶时，乳糖酶信使核糖核酸的量在回肠末端特异性下降。乳糖酶信使核糖核酸的这种减少始于回盲交界处，逐渐向空肠发展，并在数天后伴随着乳糖酶活性的下降。饥饿和再喂养也被发现会导致乳糖酶活性和信使核糖核酸表达的改变，这些改变在小肠远端尤为明显。这些数据支持，转录后和翻译前水平的调控对于确定大鼠小肠中乳糖酶的时空表达是必需的。
