Hormonal regulation of postprandial induction of gastrointestinal ornithine decarboxylase activity.
Hormonal regulation of postprandial induction of gastrointestinal ornithine decarboxylase activity.
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餐后诱导胃肠道鸟氨酸脱羧酶活性的激素调节。
DOI：
10.1152/ajpgi.1986.251.4.g460
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Seidel,ER
中科院分区：
文献类型：
--
作者：
Seidel,ER
胃肠粘膜的生长与饮食的摄入和消化有关，禁食导致粘膜发育不全，进食过多导致粘膜增生。设计实验以确定进食后多胺代谢的诱导是否与粘膜生长有关。空肠和回肠中（但十二指肠中）鸟氨酸脱羧酶（ODC）的活性取决于肠道中食物的存在；进食大鼠粘膜中的 ODC 活性比禁食大鼠高 200 倍以上。用二氟甲基鸟氨酸抑制 ODC 会导致回肠粘膜萎缩，但不会导致十二指肠粘膜萎缩。禁食大鼠的重新喂养导致十二指肠、回肠和结肠粘膜中 ODC 的显着诱导，但胃底粘膜没有显着诱导。此外，表皮生长因子和胰高血糖素这两种激素是回肠 ODC 活性的有效诱导剂。接受回肠绕道手术的大鼠实验提供了激素参与餐后粘膜 ODC 活性升高的直接证据。重新喂食禁食的大鼠后，在保持连续性的回肠和绕过的部分中诱导粘膜ODC活性。元素饮食的重新喂养表明，单独摄入碳水化合物就足以诱导最大程度的酶诱导。混合氨基酸或三油酸甘油酯并不比纤维素或糖精的非营养性溶液更有效的诱导剂。这些数据表明，在膳食摄入和消化过程中释放的激素是诱导粘膜多胺代谢的刺激物，表明食物诱导的粘膜生长是激素介导的。
The growth of gastrointestinal mucosa can be related to ingestion and digestion of diet, with fasting producing mucosal hypoplasia and hyperphagia producing mucosal hyperplasia. Experiments were designed to determine whether induction of polyamine metabolism following ingestion of a meal was related to mucosal growth. Activity of the enzyme ornithine decarboxylase (ODC) in both jejunum and ileum but not in duodenum was dependent on the presence of food in the gut; ODC activity was more than 200-fold greater in mucosa of fed rats than in fasted rats. Inhibition of ODC with difluoromethylornithine lead to mucosal atrophy in ileum but not in duodenum. Refeeding of fasted rats resulted in significant induction of ODC in duodenal, ileal, and colonic, but not fundic, mucosa. In addition, two hormones, epidermal growth factor and glucagon, were effective inducers of ileal ODC activity. Direct evidence for hormonal involvement in the postprandial rise in mucosal ODC activity was provided by experiments in rats that had undergone ileal bypass surgery. After refeeding of fasted rats mucosal ODC activity was induced in both ileum left in continuity and in the bypassed segment. Refeeding of elemental diets demonstrated that ingestion of carbohydrate alone was sufficient for maximal enzyme induction. Mixed amino acids or glyceryl trioleate were no more effective inducers than nonnutritive solutions of cellulose or saccharin. These data demonstrate that hormones which are released during ingestion and digestion of a meal are the stimuli for induction of mucosal polyamine metabolism, suggesting that food-induced mucosal growth is hormonally mediated.