Ontogeny of sucrase-isomaltase gene expression in rat intestine: responsiveness to glucocorticoids.
Ontogeny of sucrase-isomaltase gene expression in rat intestine: responsiveness to glucocorticoids.
复制标题
大鼠肠道中蔗糖酶-异麦芽糖酶基因表达的个体发育：对糖皮质激素的反应。
DOI：
10.1152/ajpgi.1993.264.2.g306
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Henning,SJ
中科院分区：
文献类型：
--
作者：
Nanthakumar,NN;Henning,SJ
我们研究的目的是确定出生后第二周和第三周糖皮质激素如何调节大鼠小肠中的蔗糖酶-异麦芽糖酶（SI）基因表达。 SI mRNA 通过 Northern blot 进行定量，并与相同组织样品中的蔗糖酶活性进行比较。通过测量出生后第 9 天肾上腺切除 (ADX) 幼鼠的 SI mRNA 和酶活性来评估内源性糖皮质激素的作用。与假手术对照幼鼠相比，ADX 幼鼠的蔗糖酶活性表现迟缓，并且 SI mRNA 的出现与酶活性平行。为了确定外源性糖皮质激素的作用，从第 10 天、第 16 天和第 18 天开始，在三个系列的实验中每天给予饱和剂量的地塞米松 (Dex)。在第 10 天的系列中，Dex 导致 SI mRNA 和蔗糖酶活性过早出现。在第16天系列中，Dex加快了这两个参数的上升速度，而到第18天，Dex没有显着影响。为了研究第 16 天系列中的加速上升是否与上皮细胞动力学的变化相关，通过免疫荧光染色评估了 SI 蛋白的位置。结果表明，Dex 在这个年龄段的作用是由于肠隐窝中带有 SI 的肠细胞更快出现。（摘要截断为 250 字）
The goal of our study was to determine how sucrase-isomaltase (SI) gene expression in the rat small intestine is modulated by glucocorticoids during the second and third postnatal weeks. SI mRNA was quantitated by Northern blot and was compared with sucrase activities in the same tissue samples. The role of endogenous glucocorticoids was assessed by measuring SI mRNA and enzyme activity in rat pups adrenalectomized (ADX) on postnatal day 9. ADX pups showed a retarded appearance of sucrase activity compared with sham-operated control pups, and the appearance of SI mRNA paralleled the enzyme activity. To determine the role of exogenous glucocorticoids, a saturating dose of dexamethasone (Dex) was administered daily in three series of experiments starting on days 10, 16, and 18. In the day 10 series, Dex caused precocious appearance of both SI mRNA and sucrase activity. In the day 16 series, Dex accelerated the rate of rise of the two parameters, whereas by day 18 there was no significant effect of Dex. To investigate whether the accelerated rise in the day 16 series was associated with changes in epithelial cell kinetics, the location of SI protein was assessed by immunofluorescence staining. The results indicated that the effect of Dex at this age was due to faster emergence of SI-bearing enterocytes from the intestinal crypts.(ABSTRACT TRUNCATED AT 250 WORDS)