生长抑素(Somatostatin, SS)及其结构相似多肽Cortistatin (CST)在抑制哺乳动物垂体激素(如生长激素)释放过程中起重要作用。但SS和CST对家鸡垂体激素的作用及其调节机制仍待阐明。 本研究拟在申请者成功鉴定家鸡'真正生长激素释放激素(GHRH)'的基础上，围绕SS、CST及其五个受体(SSTR1-5)，采用多种实验方法，探究其对家鸡垂体生长激素和催乳素生成释放的调节机制。内容包括：1) SS和CST可否以5个SSTR作为功能性受体? 2) 5种SSTR在家鸡垂体中的细胞定位；3) SS、CST可否作为抑制（或刺激）因子，参与调节GHRH、VIP等诱导的垂体生长激素和催乳素生成释放，或影响其本底水平？ 研究结果预期在垂体水平上初步构建'SS、CST对家鸡生长激素和催乳素的调控理论模型'。同时，结果亦有望从比较内分泌角度，解析不同脊椎动物类群垂体功能调节机制异同。

It has been reported that somatostatin (SS) and its structurally related cortistatin (CST) peptide play important roles in controlling the release of pituitary hormones including growth hormone (GH) in mammals; however, the roles of SS and CST, and their receptors in the pituitary of chickens remains largely unknown. The identification of authentic growth hormone-releasing hormone (GHRH) and its receptors in chickens leads us to hypothesize that SS, CST and their receptors (SSTR) may also play roles in controlling pituitary growth hormone and prolactin secretion, such as inhibition of GHRH-induced GH release. To substantiate this hypothesis, using multiple experimental techniques, present study aims to: 1) determine whether the 5 somatostatin receptors (SSTR) identified in chickens can function as the receptors specific for SS, or CST or for both peptides; 2) investigate the spatio-temporal expression patterns of 5 SSTRs in developing chicken pituitary; 3) to determine whether SS and CST can act as the inhibitory (or stimulatory) factors to regulate the basal levels of pituitary hormone (GH and PRL) expression and secretion, or GHRH (VIP and other factors)-induced hormone (GH and PRL) release. The results from present study will not only establish a basis to elucidate the role of SS and CST in controlling pituitary functions of chickens, but also provide invaluable insights into the conserved roles of SS and CST in the pituitary across vertebrates.