The Corn Protein, Zein Hydrolysate, Administered into the Ileum Attenuates Hyperglycemia via Its Dual Action on Glucagon-Like Peptide-1 Secretion and Dipeptidyl Peptidase-IV Activity in Rats
The Corn Protein, Zein Hydrolysate, Administered into the Ileum Attenuates Hyperglycemia via Its Dual Action on Glucagon-Like Peptide-1 Secretion and Dipeptidyl Peptidase-IV Activity in Rats
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DOI：
10.1210/en.2009-1510
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发表时间：
2010-07-01
期刊：
影响因子：
4.8
通讯作者：
Hara, Hiroshi
中科院分区：
文献类型：
--
作者：
Mochida, Taisuke;Hira, Tohru;Hara, Hiroshi
我们先前表明，从玉米醇溶蛋白制备的水解产物[玉米醇溶蛋白水解产物（ZeinH）]强烈刺激胰高血糖素样肽-1（GLP-1）分泌的小鼠GLP-1生产肠内分泌细胞系和大鼠小肠，特别是在回肠。在这里，我们研究了ZeinH是否通过刺激GLP-1分泌而影响回肠的葡萄糖耐量。为了观察鲁米那玉米醇溶蛋白H本身对GLP-1分泌和胰高血糖素的影响，在清醒大鼠中用回肠和颈静脉导管进行ip葡萄糖耐量试验，并测量血浆葡萄糖、胰岛素和GLP-1（总的和活性的）。此外，血浆二肽基肽酶-IV活性在回肠静脉后，ZeinH的管理到回肠结扎环在麻醉大鼠。ZeinH的回肠给药减弱葡萄糖诱导的高血糖伴随着胰岛素分泌的增强，而肉类水解物（MHY）既不诱导胰岛素分泌也不减弱高血糖。口服ZeinH也证明了其抗高血糖作用。根据这些结果，可以预测ZeinH的GLP-1释放效力高于MHY。然而，两种肽在回肠施用后诱导总GLP-1浓度的类似增加。相反，活性GLP-1浓度仅在ZeinH处理的大鼠中增加。在麻醉大鼠中，回肠给药ZeinH，但不是MHY，降低血浆二肽基肽酶-IV活性在回肠静脉。这些结果表明，回肠施用膳食肽ZeinH具有诱导GLP-1分泌和抑制GLP-1降解的双重功能，导致大鼠中胰岛素分泌的增强和高血糖症的预防。（内分泌学151：3095-3104，2010）
We previously showed that a hydrolysate prepared from corn zein [zein hydrolysate (ZeinH)] strongly stimulates glucagons-like peptide-1 (GLP-1) secretion from the murine GLP-1-producing enteroendocrine cell line and in the rat small intestine, especially in the ileum. Here, we investigated whether ZeinH administered into the ileum affects glucose tolerance via stimulating GLP-1 secretion. To observe the effect of luminal ZeinH itself on GLP-1 secretion and glycemia, ip glucose tolerance tests were performed in conscious rats with ileal and jugular catheters, and plasma glucose, insulin, and GLP-1 (total and active) were measured. In addition, plasma dipeptidyl peptidase-IV activities in the ileal vein were measured after the administration of ZeinH into the ileal-ligated loop in anesthetized rats. The ileal administration of ZeinH attenuated the glucose-induced hyperglycemia accompanied by the enhancement of insulin secretion, whereas meat hydrolysate (MHY) neither induced insulin secretion nor attenuated hyperglycemia. The antihyperglycemic effect was also demonstrated by the oral administration of ZeinH. From these results, it was predicted that the GLP-1-releasing potency of ZeinH was higher than that of MHY. However, both peptides induced a similar increase in total GLP-1 concentration after the ileal administration. In contrast, active GLP-1 concentration was increased only in ZeinH-treated rats. In anesthetized rats, ileal administration of ZeinH, but not MHY, decreased plasma dipeptidyl peptidase-IV activity in the ileal vein. These results indicate that the ileal administration of a dietary peptide, ZeinH, has the dual functions of inducing GLP-1 secretion and inhibiting GLP-1 degradation, resulting in the enhancement of insulin secretion and the prevention of hyperglycemia in rats. (Endocrinology 151: 3095-3104, 2010)