HORMONAL CONTROL OF C-KINASE AND CORPUS LUTEUM FUNCTION

哺乳动物的黄体是一种 暂时腺 在月经 或者说发情周期，它会发育，分泌孕酮一段时间 物种的特征，然后下降。 在人类和 奶牛，调节黄体功能的热带因子已被 证明主要是促黄体生成激素（LH）和人类 绒毛膜促性腺激素 然而，这些机制的影响， LH在细胞和分子水平上的增殖仍然是一个谜。 众所周知，孕酮分泌与 LH增加cAMP和激活cAMP依赖蛋白能力 激酶，但最近的证据表明，另一种途径导致 卵巢蛋白的磷酸化。 这条途径与 肌醇磷脂的水解、钙流和刺激 钙依赖性蛋白激酶;一种这样的激酶，蛋白激酶C， 参与调节多种细胞活动， 卵巢细胞 重要的是，最近的证据清楚地表明， 蛋白激酶C酶家族的存在， 组织，每个组织显示不同的生化特性， 组织分布和发育表达。 的具体目标 建议的研究是鉴定和表征蛋白激酶C 牛黄体同工酶。 该提案将全面关注 表征卵巢蛋白激酶C同工酶并记录其 生理条件下的组织分布和发育表达 牛的相关情况。 蛋白激酶活性的测量 将与特定蛋白激酶C的mRNA水平进行比较 同工酶 牛小黄体细胞和大黄体细胞的培养将提供 蛋白激酶C的激素调节所需的信息 在规定条件下的同工酶。 这些研究有望改善 我们对LH和其他激素作用机制的了解， 控制黄体的发育和功能。 理解 这些调节机制可能导致生育方法的改进 控制

The mammalian corpus luteum is a transient gland. During the menstrual or estrous cycle, it develops, secretes progesterone for a period of time characteristic of the species, and then declines. In the human and the cow, the tropic factors which regulate luteal function have been demonstrated to be predominantly luteinizing hormone (LH) and human chorionic gonadotropin. However, the mechanisms by which the effects of LH are propagated at the cellular and molecular level remain a mystery. It is well recognized that progesterone secretion is closely coupled to the ability of LH to increase cAMP and activate cAMP-dependent protein kinases but recent evidence implicates another pathway resulting in the phosphorylation of ovarian proteins. This pathway is linked to the hydrolysis of inositol phospholipids, calcium flux and stimulation of calcium dependent protein kinases; one such kinase, protein kinase C, has been implicated in the regulation of a variety of cellular activities in ovarian cells. Importantly, recent evidence has clearly demonstrated the existence of a family of protein kinase C enzymes in hormone-responsive tissues, each displaying different biochemical properties, tissue-distribution and developmental expression. The specific aims of the proposed research are to identify and characterize protein kinase C isozymes in the bovine corpus luteum. This proposal will focus on fully characterizing ovarian protein kinase C isozymes and documenting their tissue distribution and developmental expression under physiologically relevant conditions in the cow. Measurements of protein kinase activity will be compared with levels of mRNA for specific protein kinase C isozymes. Cultures of bovine small and large luteal cells will provide needed information on the hormonal regulation of protein kinase C isozymes under defined conditions. These studies are expected to improve our knowledge of the mechanism of action of LH and other hormones which control the development and function of the corpus luteum. Understanding these regulatory mechanisms may lead to improved methods of fertility control.