Overduin T Sebastian, Clarke Georgia S, Li Hui, Young Richard L, Gatford Kathryn L, Page Amanda J
School of Biomedicine, The University of Adelaide, Adelaide, South Australia, Australia.
Nutrition, Diabetes & Gut Health, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia.
Physiol Rep. 2025 Aug;13(15):e70493. doi: 10.14814/phy2.70493.
Pregnancy demands increased food intake and nutrient delivery to support the growing conceptus. The timing and regional specificity of adaptations in small intestinal (SI) anatomy and transport, and their functional consequences, remain unclear. We therefore assessed anatomy and expression of macronutrient transporters in the duodenum, jejunum, and ileum collected from time-mated pregnant C57BL/6 mice at gestational day (GD) 6.5, 12.5, or 17.5 and age-matched nonpregnant females. Ex vivo active glucose transport was measured in each SI region of nonpregnant and GD17.5 mice. The SI was 20% heavier (p < 0.001) and 10% longer (p = 0.027) and SI villi were 18% longer (p < 0.001) in late pregnant than nonpregnant mice. Differences in relative carbohydrate (Slc5a1, Slc2a2, and Slc2a5) and amino acid (Slc6a19) transporter expression between pregnancy stages were region-specific, while expression of the fatty acid transporter Fabp2 was lower in all pregnant groups. Despite anatomical and molecular changes in support of an increase in SI capacity for nutrient absorption, active glucose transport per unit area was similar in nonpregnant and late-pregnant mice. Increased nutrient demand during pregnancy may therefore be met largely through SI expansion and slower nutrient transit, although contributions of other nutrient transport mechanisms require evaluation.
怀孕需要增加食物摄入量和营养物质输送，以支持不断生长的胎儿。小肠（SI）解剖结构和转运的适应性变化的时间和区域特异性及其功能后果仍不清楚。因此，我们评估了从妊娠第（GD）6.5、12.5或17.5天的同期受孕C57BL/6小鼠以及年龄匹配的未孕雌性小鼠收集的十二指肠、空肠和回肠中大量营养素转运蛋白的解剖结构和表达。在未孕和GD17.5小鼠的每个SI区域测量了体外活性葡萄糖转运。与未孕小鼠相比，妊娠后期小鼠的SI重20%（p < 0.001），长10%（p = 0.027），SI绒毛长18%（p < 0.001）。妊娠阶段之间相对碳水化合物（Slc5a1、Slc2a2和Slc2a5）和氨基酸（Slc6a19）转运蛋白表达的差异具有区域特异性，而脂肪酸转运蛋白Fabp2的表达在所有妊娠组中均较低。尽管在支持SI营养吸收能力增加方面存在解剖学和分子变化，但未孕和妊娠后期小鼠每单位面积的活性葡萄糖转运相似。因此，怀孕期间增加的营养需求可能很大程度上通过SI扩张和营养物质转运减慢来满足，尽管其他营养物质转运机制的作用需要评估。
