Ghrelin is present in pancreatic α-cells of humans and rats and stimulates insulin secretion
Ghrelin is present in pancreatic α-cells of humans and rats and stimulates insulin secretion
复制标题
DOI：
10.2337/diabetes.51.1.124
复制
发表时间：
2002-01-01
期刊：
影响因子：
7.7
通讯作者：
Matsukura, S
中科院分区：
文献类型：
--
作者：
Date, Y;Nakazato, M;Matsukura, S
Ghrelin是从人和大鼠胃中分离的一种新的生长激素释放肽，是一种具有翻译后酰化修饰的28个氨基酸的肽，其通过增加细胞内Ca 2+浓度来刺激生长激素分泌是不可缺少的。它还具有调节摄食行为、能量代谢、胃酸分泌和运动的功能。使用两种不同的抗体对NH 2-和COOH-末端区域的ghrelin，我们研究了其在人类和大鼠胰腺的定位免疫组织化学。在这两个物种的胰岛周围都发现了饥饿素免疫反应细胞。在大鼠胰岛中，Ghrelin仅与胰高血糖素共定位，表明其在α细胞中产生。我们确定了生长素和des-acyl生长素在大鼠胰腺使用反相高效液相色谱结合两个放射免疫分析。我们还在大鼠胰岛中检测了Ghrelin及其受体的mRNA。Ghrelin增加β-细胞胞浆游离Ca ~（2+）浓度，刺激胰岛分泌胰岛素。这些发现表明，生长激素释放肽可能调节胰岛功能的内分泌和/或旁分泌的方式。
Ghrelin, a novel growth hormone-releasing peptide isolated from human and rat stomach, is a 28-amino acid peptide with a posttranslational acylation modification that is indispensable for stimulating growth hormone secretion by increasing intracellular Ca2+ concentration. It also functions in the regulation of feeding behavior, energy metabolism, and gastric acid secretion and motility. Using two different antibodies against the NH2- and COOH-terminal regions of ghrelin, we studied its localization in human and rat pancreas by immunohistochemistry. Ghrelin-immunoreactive cells were identified at the periphery of pancreatic islets in both species. Ghrelin co-localized exclusively with glucagon in rat islets, indicating that it is produced in alpha-cells. We identified ghrelin and des-acyl ghrelin in the rat pancreas using reverse-phase high-performance liquid chromatography combined with two radioimmunoassays. We also detected mRNA encoding ghrelin and its receptor in the rat pancreatic islets. Ghrelin increased the cytosolic free Ca2+ concentration in beta-cells and stimulated insulin secretion when it was added to isolated rat pancreatic islets. These findings indicate that ghrelin may regulate islet function in an endocrine and/or paracrine manner.