Dietary modulation of intestinal fructose transport and GLUT5 mRNA expression in hypothyroid rat pups.
Dietary modulation of intestinal fructose transport and GLUT5 mRNA expression in hypothyroid rat pups.
复制标题
甲状腺功能减退大鼠幼仔肠道果糖转运和 GLUT5 mRNA 表达的饮食调节。
DOI：
10.1097/00005176-199911000-00017
复制
发表时间：
1999
影响因子：
2.9
通讯作者：
Ferraris,RP
中科院分区：
文献类型：
--
作者：
Monteiro,IM;Jiang,L;Ferraris,RP
在正常断奶的大鼠中，肠道果糖转运率或GLUT5 mRNA水平通常在断奶后增加2 - 3倍，但在断奶早期通过高果糖饮食可以提前增强。血清甲状腺素水平的发育增加与断奶的开始一致，并与肠道蔗糖酶和乳糖酶活性的变化有关。方法从妊娠第18天起，以0.01%丙硫脲嘧啶坝为饮水，使大鼠甲状腺功能减退。然后，从17日龄开始，每天两次灌喂高果糖或高葡萄糖溶液，持续3天，然后在20日龄时杀死甲状腺功能低下的幼崽和与年龄匹配的正常甲状腺对照组幼崽。结果甲状腺功能减退犬血清甲状腺素水平降低5倍。喂食高果糖溶液的甲状腺功能低下和甲状腺功能正常的幼崽，其近端和中小肠的肠道果糖摄取率比喂食高葡萄糖溶液或正常断奶的幼崽高2.0至2.5倍。在甲状腺功能低下的幼崽中，肠道葡萄糖摄取也有所增加，而在喂食高果糖或高葡萄糖溶液的正常甲状腺幼崽中则没有。在高果糖喂养的甲状腺功能正常和甲状腺功能低下的幼犬中，GLUT5 mRNA水平升高，并与果糖摄取增加平行。结论在断奶期间，饲粮中果糖可以提前提高肠道果糖摄取和GLUT5 mRNA表达，而不依赖于发育期血清甲状腺素水平的升高。葡萄糖转运率的适度变化表明，非特异性机制可能对饮食诱导的甲状腺功能减退幼犬营养吸收的变化起着很小的作用。
BackgroundIntestinal fructose transport rates or GLUT5 mRNA levels typically show a two‐ to threefold increase after weaning in rats allowed to wean normally but can be enhanced precociously by high‐fructose diets during early weaning. Developmental increases in serum thyroxine levels coincide with the onset of weaning and have been linked to changes in intestinal sucrase and lactase activities.MethodsRat pups were made hypothyroid by giving the dam 0.01% propylthiouracil as drinking water from day 18 of gestation. The hypothyroid pups and age‐matched euthyroid control pups were then fed high‐fructose or high‐glucose solutions by gavage, twice a day starting at 17 days of age for 3 days, and then killed at 20 days of age.ResultsSerum thyroxine levels were five times lower in the hypothyroid pups. Rates of intestinal fructose uptake in the proximal and middle small intestine were 2.0 to 2.5 times higher in the hypothyroid and euthyroid pups fed high‐fructose solution than in littermates fed high‐glucose solution or those allowed to wean normally with the dam. Intestinal glucose uptake also increased in hypothyroid but not in euthyroid pups fed high‐fructose or high‐glucose solutions. GLUT5 mRNA levels increased in euthyroid and hypothyroid pups fed high fructose and paralleled the increase in fructose uptake.ConclusionDuring weaning, dietary fructose can precociously enhance intestinal fructose uptake and GLUT5 mRNA expression, independent of developmental increases in serum thyroxine levels. Modest changes in glucose transport rates indicate that nonspecific mechanisms may provide a minor contribution to diet‐induced changes in nutrient absorption in hypothyroid pups.