糖皮质激素对家鸡垂体功能的调节机制初探

应激反应在脊椎动物中普遍存在。它会影响动物生长、降低繁殖性能、导致其免疫力低下。现已知应激主要由‘下丘脑-垂体-肾上腺轴’掌控。其中，糖皮质激素是HPA轴下游关键效应因子，它可在下丘脑、垂体水平上进行反馈调节，减缓应激反应。至目前，针对“糖皮质激素对垂体功能的调节机制”的系统研究相对有限。本项目拟在长期工作累积基础上，以家鸡为模型，采用多种实验方法，重点解析：(1)糖皮质激素-皮质酮(CORT)对垂体激素ACTH生成、释放的反馈调节机制；(2)CORT对生长、繁殖等相关垂体激素生成释放调节的分子机制；(3)不同应激源对垂体功能的调节机制异同。结果预期为<应激时，CORT可在垂体水平上，通过对掌控应激、生长、繁殖等垂体激素的调节，进而影响家鸡生长、繁殖性状>这一假设提供科学依据。同时，本研究亦为减缓禽类应激、提升生产性能、改善动物福利等提供参考策略。

Stress response exists in nearly all classes of vertebrates. It usually inhibits the growth, reproduction, and immune response. It is clear that stress response is tightly controlled by the genes in the hypothalamus-pituitary-adrenal axis (HPA axis). Within the HPA axis, glucocorticoid is a pivotal player in stress response, which can regulate the functions of hypothalamus and anterior pituitary in a feedback manner and thus alleviate the stress response. However, till present, it remains largely unknown how glucocorticoid could control the pituitary functions in vertebrates. On the basis of the extensive studies on chicken pituitary functions from our lab for more than ten years, this project aims to further address following issues regarding the roles of corticosterone (CORT) in chicken pituitary. (1) What is underlying mechanism of CORT-regulated ACTH (POMC) expression and secretion? (2) What is the underlying mechanism of CORT-regulated the expression and secretion of other pituitary hormones, which are associated with animal growth and reproduction etc? (3) Whether the different stress stimuli can regulate the pituitary gene expression and function similarly? The answers to these questions will help to verify our hypothesis that during stress, CORT may work on the pituitary to regulate the expression and secretion of pituitary hormones (or genes) associated with stress, growth, and reproduction etc, which may consequently affect the economic traits (growth and reproduction) of animals. Meanwhile, the results from this study will also aid to develop a strategy which may help to reduce the stress response, increase the production, and improve the welfare of animals in the future.