NEUROENDOCRINE REGULATION OF OVINE ESTROUS CYCLES

绵羊动情周期的神经内分泌调节

• 批准号: 3323495
• 负责人: SANDRA J. LEGAN
• 金额: $ 10.61万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-09-01 至 1993-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3323495
• 关键词: chorionic gonadotropin; drug delivery systems; estradiol; estrus; follicle stimulating hormone; gonadotropin releasing factor; graafian follicles; hormone receptor; hormone regulation /control mechanism; luteinizing hormone; menstrual cycle; neuroendocrine system; ovary; ovulation; progesterone; radioimmunoassay; sheep; testosterone

The long-term goal of the proposed research is to elucidate the neuro- endocrine mechanisms whereby progesterone prevents short luteal phase cycles in ewes. It has been proposed that progesterone may prevent short luteal phases by promoting folliculogenesis, by stimulating luteal function, by preventing luteolysis, or a combination of these actions. Specifically, the proposed studies will examine whether progesterone modulates some of the parameters which promote folliculogenesis, namely gonadotropin secretion, or ovarian response to gonadotropins, or both. First, we will examine whether progesterone acts solely at the ovaries. Subsequent experiments will investigate whether progesterone ensures full-length luteal phases by modulating FSH or pulsatile LH secretion. Finally, the mechanism of action of progesterone in promoting folliculogenesis within the ovary will be investigated by measuring its effect on follicular steroid production and thecal and granulosa cell binding of 125I-hCG. Techniques include: radioimmunoassays for LH, FSH, estradiol, testosterone, and progesterone; sustained delivery of hormones via osmotic minipumps or Silastic implants; blood collection; cannulation of ovarian artery; active immunization against GnRH; ovariectomy; reversible termination of cycles with GnRH agonist; in vitro incubation of granulosa cells, ad measurement of ovarian thecal and granulosa cell LH receptors. The results of these studies should: (1) provide us with new insight into the neuroendocrine mechanisms controlling estrous cycles and their initiation and termination; (2) increase our knowledge of the mechanisms controlling recovery of cyclicity following treatment with GnRH agonist; (3) increase our understanding of the neuroendocrine control of short luteal phases and the prevention of short luteal phase infertility; and (4) provide us with new information regarding the role of progesterone in promoting folliculogenesis. Finally, these findings should be applicable to the clinical situations analogous to transitions between states of acyclicity and cyclicity, such as puberty, menopause, or those occurring following treatment of precocious puberty or endometriosis with GnRH agonists, or following use of GnRH agonists as contraceptives.

拟议的研究的长期目标是阐明神经 孕酮可防止短鲁叶相的内分泌机制 母羊中的循环。 有人提出孕酮可以阻止 通过刺激黄体，通过促进卵泡发生来促进黄体相 功能，防止曲解溶解或这些作用的组合。 具体而言，拟议的研究将检查孕酮是否 调节一些促进卵泡发生的参数，即 促性腺激素分泌，或卵巢对促性腺激素的反应，或两者兼而有之。 首先，我们将检查孕酮是否仅对卵巢作用。 随后的实验将研究孕酮是否确保 通过调节FSH或脉冲LH分泌的全长黄体相。 最后，孕酮在促进中的作用机理 卵巢内的卵泡发生将通过测量其 对卵泡类固醇产生以及胸骨和颗粒细胞的影响 125i-HCG的结合。 技术包括：LH，FSH，FSH的放射免疫测定 雌二醇，睾丸激素和孕酮；持续交付 通过渗透微型植物或硅胶植入物激素；血液收集； 卵巢动脉的插管；对GNRH的主动免疫； 卵巢切除术；用GnRH激动剂对周期的可逆终止；在 颗粒细胞的体外孵育，卵巢thecal的AD测量 和颗粒细胞LH受体。 这些研究的结果应： （1）为我们提供有关神经内分泌机制的新见解 控制发情循环及其启动和终止； （2） 增加我们对控制恢复机制的了解 GnRH激动剂治疗后的循环性； （3）增加我们的 理解对短的黄体阶段的神经内分泌控制和 预防短黄体期不育症； （4）给我们 有关孕酮在促进中的作用的新信息 卵泡发生。 最后，这些发现应适用于 临床情况类似于状态之间的过渡 循环和循环性，例如青春期，更年期或发生的循环性 治疗与GNRH早熟或子宫内膜异位症后 激动剂，或使用GnRH激动剂作为避孕药。