Dietary modulation of small intestinal glutamine transport in intestinal brush border membrane vesicles of rats.
Dietary modulation of small intestinal glutamine transport in intestinal brush border membrane vesicles of rats.
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DOI：
10.1016/0022-4804(90)90244-v
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发表时间：
1990-06
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影响因子：
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通讯作者：
R. Salloum;W. Souba;Alarico Fernandez;B. Stevens
中科院分区：
文献类型：
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作者：
R. Salloum;W. Souba;Alarico Fernandez;B. Stevens
研究富含谷氨酰胺的饮食对谷氨酰胺从大鼠空肠穿过刷状缘膜囊泡（BBMV）转运的影响，以进一步了解饮食对调节肠道谷氨酰胺利用的影响。禁食后，大鼠被随机分配到三种营养完整的元素饮食中的一种，并补充谷氨酰胺、谷氨酸或甘氨酸（对照）。通过Mg2+聚集/差速离心技术制备刷状缘膜囊泡，并使用快速混合/过滤技术研究BBMV对放射性[3H]谷氨酰胺的吸收。所有测试饮食组的 BBMV 碱性磷酸酶含量均丰富 14 倍。所有组的[3H]谷氨酰胺摄取过程均表现出钠依赖性、超调和类似的2小时平衡值。与对照饮食相比，饲喂富含谷氨酰胺饮食的动物的囊泡的谷氨酰胺摄取量增加了 75%，与富含谷氨酸盐饮食的动物相比，囊泡的谷氨酰胺摄取量增加了 250% (P<0.05)。与甘露醇对照相比，α-甲氨基异丁酸和甘氨酸没有显着抑制总[3H]谷氨酰胺摄取，而天冬酰胺和谷氨酰胺抑制总[3H]谷氨酰胺摄取。刷状缘似乎具有谷氨酰胺选择性系统 N 转运蛋白，其活性可以通过提供膳食谷氨酰胺来刺激。
The effects of a glutamine-enriched diet on the transport of glutamine across brush border membrane vesicles (BBMV) from the rat jejunum were studied to gain further insight into the effects of diet on regulating gut glutamine utilization. Following fasting, rats were randomized to one of three nutritionally complete elemental diets supplemented with glutamine, glutamate, or glycine (control). Brush border membrane vesicles were prepared by a Mg2+aggregation/differential centrifugation technique and uptake of radioactive [3H]glutamine by the BBMV was studied using a rapid mixing/filtration technique. BBMVs from all test diet groups were enriched in alkaline phosphatase 14-fold. [3H]Glutamine uptake courses for all groups demonstrated sodium dependency, overshoots, and similar 2-hr equilibrium values. Vesicles from animals fed the glutamine-enriched diet had a 75% increase in glutamine uptake compared to those of the control diet and a 250% increase compared to those of the glutamate-enriched diet (P< 0.05). α-Methylamino isobutyric acid and glycine did not significantly inhibit total [3H]glutamine uptake, whereas asparagine and glutamine inhibited total [3H]glutamine uptake compared to the mannitol control. The brush border appears to possess the glutamine selective System N transporter, the activity of which can be stimulated by providing dietary glutamine.