Increased expression of ileal apical sodium-dependent bile acid transporter in postpartum rats
Increased expression of ileal apical sodium-dependent bile acid transporter in postpartum rats
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DOI：
10.1152/ajpgi.00309.2001
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发表时间：
2002-01-01
影响因子：
4.5
通讯作者：
Vore, M
中科院分区：
文献类型：
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作者：
Mottino, AD;Hoffman, T;Vore, M
在对照组、妊娠组和产后哺乳组大鼠的小肠中检测了顶端回肠钠依赖性胆汁酸转运体（asbt）在分娩后第2、12和21天的表达和活性。从小肠的不同区域制备的刷状缘膜囊泡（BBMV）的蛋白质印迹分析表明，asbt的表达是最大的最远段的所有实验组，在怀孕和产后2天的大鼠没有实质性的影响，并在产后12天和21天的大鼠显着增加。mRNA分析表明，产后大鼠asbt蛋白在转录后水平受到调控。在产后14- 21天的大鼠中，在回肠近端区域，产后asbt蛋白的表达增加最大（接近2倍），这与BBMV中牛磺胆酸盐（TC）从回肠近端转运的增加60%相一致。TC的吸收，确定从完整的近端回肠使用肠袢模型，表现出增加30%的TC摄取每单位重量的组织在产后14至21天的大鼠相对于对照组大鼠。连同在泌乳高峰期观察到的肠道质量的显著增加，这些数据表明在泌乳大鼠肠道中asbt介导的胆汁酸回收显著增加。
The expression and activity of the apical ileal sodium-dependent bile acid transporter (asbt) was examined in the small intestine of control, pregnant, and lactating postpartum rats 2, 12, and 21 days after delivery. Western blot analysis of brush border membrane vesicles (BBMV) prepared from different regions of the small intestine demonstrated that expression of asbt was maximal in the most distal segments for all experimental groups, was not substantially affected in pregnant and 2-day postpartum rats, and was significantly increased in 12- and 21-day postpartum rats. Analysis of mRNA suggested that asbt protein was regulated at the posttranscriptional level in postpartum rats. Increased expression of asbt protein postpartum was maximal (similar to2-fold) in the proximal region of the ileum, consistent with a 60% increase in taurocholate (TC) transport in BBMV from the proximal ileum in 14- to 21-day postpartum rats relative to control rats. Absorption of TC, determined from the intact proximal ileum using an intestinal loop model, demonstrated a 30% increase in TC uptake per unit weight of tissue in 14- to 21-day postpartum rats relative to control rats. Together with the marked increase in intestinal mass observed at peak lactation, these data indicate a significant increase in asbt-mediated reclamation of bile acids in the intestine of lactating rats.