Oesterreicher T J, Nanthakumar N N, Winston J H, Henning S J
Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA.
Am J Physiol. 1998 May;274(5):R1220-7. doi: 10.1152/ajpregu.1998.274.5.R1220.
A partial rat trehalase cDNA has been cloned and used to examine trehalase mRNA expression. Northern blotting with total RNA from 11 adult rat tissues showed a trehalase transcript only in small intestine, where it was abundant in proximal regions but declined steeply toward the ileum. During development, trehalase mRNA was not detectable in jejunum until postnatal day 19 and then increased markedly through day 25. Modest levels in trehalase mRNA were induced precociously by administration of dexamethasone, with increasing responsiveness evident between the first and second postnatal weeks. In contrast, analysis of sucrase-isomaltase mRNA on the same blots showed maximal induction at both ages. In adrenalectomized animals, the ontogenic increase of trehalase mRNA began as usual but proceeded more slowly than in control animals. Overall, trehalase mRNA expression in the rat displayed both similarities and differences compared with rabbit. Moreover, the differences revealed in glucocorticoid responsiveness of trehalase mRNA and sucrase-isomaltase mRNA suggest that the actions of these hormones on the developing intestine may be more complex than previously recognized.
已克隆出部分大鼠海藻糖酶cDNA，并用于检测海藻糖酶mRNA的表达。对11种成年大鼠组织的总RNA进行Northern印迹分析显示，仅在小肠中存在海藻糖酶转录物，在小肠近端区域含量丰富，但向回肠方向急剧下降。在发育过程中，空肠中直到出生后第19天才可检测到海藻糖酶mRNA，然后在第25天之前显著增加。给予地塞米松可早熟诱导海藻糖酶mRNA达到适度水平，在出生后第一周和第二周之间反应性增加明显。相比之下，对同一印迹上蔗糖酶-异麦芽糖酶mRNA的分析显示，在两个年龄段均有最大诱导。在肾上腺切除的动物中，海藻糖酶mRNA的个体发育性增加如往常一样开始，但比对照动物进行得更慢。总体而言，与兔子相比，大鼠中海藻糖酶mRNA的表达既有相似之处也有差异。此外，海藻糖酶mRNA和蔗糖酶-异麦芽糖酶mRNA在糖皮质激素反应性上的差异表明，这些激素对发育中小肠的作用可能比以前认识到的更为复杂。
