Dietary-induced rapid decrease of microvillar carbohydrase activity in rat jejunoileum.
Dietary-induced rapid decrease of microvillar carbohydrase activity in rat jejunoileum.
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DOI：
10.1152/ajpgi.1983.245.3.g418
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发表时间：
1983-09
期刊：
影响因子：
--
通讯作者：
T. Goda;K. Yamada;S. Bustamante;O. Koldovský
中科院分区：
文献类型：
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作者：
T. Goda;K. Yamada;S. Bustamante;O. Koldovský
测定了 16 周龄雌性大鼠空肠近端、中端和远端 1/3 的几种糖酶和肽酶的活性，这些大鼠被喂食高淀粉（70 cal%）、低脂肪（7 cal%）饮食 2 周，并且在大鼠（在此介绍期之后）被喂食等热量低淀粉（5 cal%）、高脂肪（73 cal%）饮食 2 周。 1、2 和 3 天。在这些实验期间，所有组的体重变化、食物摄入量、每个肠段的蛋白质含量和肠上皮细胞迁移率实际上是相同的。淀粉摄入量减少后，空肠绒毛隐窝柱所有区域（主要是近端和中段）的总肠匀浆中的糖酶（乳糖酶、蔗糖酶、麦芽糖酶和葡糖淀粉酶）在最初 24 小时内迅速减少（40-80%）——正如在低温恒温器系列切片中所研究的那样。相比之下，亮氨酰萘酰胺酶和L-苯丙氨酰甘氨酸水解酶的活性除了在第一天仅近端节段的活性略有暂时降低（25-30%）外几乎没有变化。因此，这些数据表明，等热量饮食中淀粉含量的减少引起微绒毛糖酶活性的快速降低，并且成熟和未成熟肠细胞中这些酶的活性能够对饮食碳水化合物含量的变化（减少）做出反应。
Activities of several carbohydrases and peptidases were determined in proximal, middle, and distal thirds of the jejunoileum of female 16-wk-old rats that were fed a high-starch (70 cal%), low-fat (7 cal%) diet for 2 wk and also in rats that (after this introductory period) were fed an isocaloric low-starch (5 cal%), high-fat (73 cal%) diet for 1, 2, and 3 days. The body weight changes, food intake, amount of protein per intestinal segment, and rate of enterocyte migration were practically the same in all groups during these experimental periods. The decreased intake of starch was followed by a rapid decrease (40-80%) of carbohydrases (lactase, sucrase, maltase, and glucoamylase) within the first 24 h in total intestinal homogenates--and as studied in cryostat serial sections--in all regions of the jejunal villus-crypt columns, and mainly in proximal and middle segments. In contrast, the activities of leucylnaphthylamidase and L-phenylalanylglycine hydrolase exhibited little change except for a slight temporary decrease of activity on the 1st day in the proximal segment only (25-30%). Thus these data show that a decrease of starch content in an isocaloric diet evokes a rapid decrease in the activity of microvillar carbohydrases and that activity of these enzymes both in mature and immature enterocytes is capable of reacting to a change (decrease) of dietary carbohydrate content.