胃泌素释放肽（GRP）因具有促进胃泌素（Gastrin）分泌而得名。我们已有研究显示GRP和胃泌素均可升高反刍动物生长激素（GH）水平，但GH升高时相显著不同，推测这两种激素在促进GH分泌方面具有不同的机制。本项目通过在体受体阻断策略探究生长激素释放激素（GHRH）、生长抑素（SS）和Ghrelin对胃泌素和GRP引起的GH水平升高的影响；通过垂体细胞培养，揭示GHRH、SS和Ghrelin是否参与胃泌素和GRP调控GH分泌及可能的信号途径（cAMP、cGMP、PKA和PKC）；用免疫组化方法探究胃泌素受体和GRP受体在反刍动物各组织的分布并观察在垂体GH和皱胃Ghrelin的内分泌细胞上是否有这两种受体的定位，以从组织学角度探明胃泌素或GRP是否直接调控垂体GH的分泌。期望通过本项目实施，揭示胃泌素和GRP上调反刍动物GH分泌时相差异的可能机制，为在生产实践中靶向调控动物生长提供参考。

Gastrin releasing peptide (GRP) was named due to its stimulation the release of gastrin. We have reported that plasma growth hormone (GH) levels elevated after adminstration of gastrin or GRP in ruminants, but its effect was significantly different in time course , suggesting that these two hormones in promoting GH secretion with different mechanisms. In the present study, we plan: 1 ) to explore whether growth hormone releasing hormone (GHRH) and somatostatin (SS) involve in gastrin and GRP induced GH increase in vivo by the strategies of receptor block; 2 ) to reveal whether GHRH, SS and ghrelin involve in gastrin and GRP induced GH increase and their possible signaling pathways (cAMP, cGMP, PKA and PKC) through pituitary cell culture; 3) to explore the histological distribution of gastrin / CCK-B receptors and GRP-R receptors, and to observe whether there are the two kinds of receptors in GH endocrine cells in ruminants. Through this study, we hope to understand the different mechanisms that GH secretion induced by gastrin and GRP in ruminants. The results from this program will provide the data for target regulation growth in ruminants.