Regulation of proline and glucose transport in mouse intestine by dietary substrate levels.
Regulation of proline and glucose transport in mouse intestine by dietary substrate levels.
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DOI：
10.1073/pnas.80.24.7674
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发表时间：
1983-12
影响因子：
11.1
通讯作者：
W. Karasov;R. S. Pond;D. Solberg;J. Diamond
中科院分区：
文献类型：
--
作者：
W. Karasov;R. S. Pond;D. Solberg;J. Diamond
在改变小鼠饮食碳水化合物和蛋白质水平的实验中，我们测量了小鼠肠套在50 mM处对d -葡萄糖和l -脯氨酸的主动摄取。与几乎不含碳水化合物的肉类饮食相比，50%碳水化合物的实验室饲料刺激了近端肠的主动葡萄糖摄取，而不影响脯氨酸摄取、被动葡萄糖通透性或粘膜质量的几项指标。从低蛋白高碳水化合物饮食到高蛋白无碳水化合物饮食的转换可逆地刺激了脯氨酸的摄取，同时抑制了葡萄糖的摄取。每次转换溶质和饮食，转运刺激在1天内完成，而抑制则需要数天。结果表明，饲粮底物水平对肠道葡萄糖和脯氨酸运输有诱导和抑制作用。这一机制，连同营养物质浓度沿肠的正常梯度，可能是营养物质沿肠运输梯度的主要原因。
Active uptake of D-glucose and L-proline at 50 mM was measured in everted intestinal sleeves of mice whose dietary carbohydrate and protein levels were being varied experimentally. Compared to a nearly carbohydrate-free meat diet, a 50% carbohydrate laboratory chow diet stimulated active glucose uptake in the proximal intestine without affecting proline uptake, passive glucose permeability, or several measures of mucosal mass. Switching from a low-protein high-carbohydrate to a high-protein no-carbohydrate diet reversibly stimulated proline uptake while inhibiting glucose uptake. For each solute and diet switch, the stimulation of transport was complete within 1 day, while the inhibition required several days. The results imply induction and repression of intestinal glucose and proline transport by dietary substrate levels. This mechanism, in conjunction with the normal gradient of nutrient concentrations along the intestine, is probably largely responsible for the gradient in nutrient transport along the intestine.