Ontogenetic development of monosaccharide and amino acid transporters in rabbit intestine.
Ontogenetic development of monosaccharide and amino acid transporters in rabbit intestine.
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兔肠道单糖和氨基酸转运蛋白的个体发育。
DOI：
10.1152/ajpgi.1990.259.4.g544
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Diamond,JM
中科院分区：
文献类型：
--
作者：
Buddington,RK;Diamond,JM
我们测量了从出生到成年兔肠道对7种糖和氨基酸的刷状缘摄取量随年龄的变化。肠道尺寸，特别是结肠和盲肠的尺寸，随着体重的增加而增加的速度比兔子在生长过程中保持相同比例时更快。然而，标称小肠面积的增加与动物的基础代谢率大致成正比。对于除果糖外的所有溶质，每毫克肠组织的摄取在出生时或接近出生时最大，并在成人中下降到低2.5-5倍的水平。然而，由于小肠的生长，小肠全长的总吸收能力与代谢率大致成正比地增加。每毫克果糖的摄取量在断奶时急剧增加是独一无二的，这与断奶后天然饮食中首次出现果糖有关。在醛己糖或氨基酸之间的摄取比率的ESTA相关的变化表明相关的转运蛋白的发育序列。与非常高的蛋白质含量的兔乳，脯氨酸葡萄糖摄取率是较高的哺乳兔比其他哺乳动物。值得注意的是，成年兔的比率高于其他单胃食草动物，而与食肉动物的值相似。在解释中，虽然小肠的运输能力似乎占脯氨酸的吸收在所有年龄的兔子和糖的吸收在哺乳兔，后肠可能是一个主要的网站碳水化合物消化成年兔。
We measured brush-border uptakes of seven sugars and amino acids by rabbit intestine as a function of age from the day of birth to adulthood. Gut dimensions, especially those of the colon and cecum, increase more rapidly with body weight than would be true if rabbits maintained identical proportions as they grew. However, nominal small intestinal area increases in approximately direct proportion to the animal's basal metabolic rate. For all solutes except fructose, uptake per milligram of intestinal tissue is maximal at or near birth and declines to a level 2.5-5 times lower in the adult. Because of small intestinal growth, though, the total uptake capacity of the whole length of the small intestine increases in approximately direct proportion to metabolic rate. Fructose uptake per milligram is unique in increasing steeply at the time of weaning, correlated with the post-weaning first appearance of fructose in the natural diet. Age-related changes in uptake ratios among aldohexoses or amino acids suggest developmental sequences of related transporters. Correlated with the very high protein content of rabbit milk, the proline-to-glucose uptake ratio is higher in suckling rabbits than in other sucking mammals. Remarkably, the ratio for adult rabbits is higher than in other monogastric herbivores and is instead similar to values for carnivores. In explanation, although the transport capacity of the small intestine appears to account for proline absorption in rabbits of all ages and for sugar absorption in suckling rabbits, the hindgut may be a major site of carbohydrate digestion in adult rabbits.