REGULATION OF SPERM EXOCYTOSIS

精子的顶体必须在精子 使卵子受精 刚射出的哺乳动物精子不能 胞吐作用它们必须首先完成一个不为人知的成熟过程 在它们成为顶体反应之前就已经开始了。长期目标 这个项目的目的是了解胞吐作用的机制， 控制。 精浆阻止精子成为顶体反应。 的 精浆中影响顶体反应性的物质将被 鉴定这个项目将使用精浆和分子分离 作为分析顶体反应控制的工具。 取决于它是如何应用于精子，精浆可以抑制 顶体反应性，反向顶体反应性， 或增强顶体反应性。因为顶体胞吐作用 由细胞内游离Ca2+浓度增加触发， 需要细胞内pH值的升高，精浆对细胞内pH值的影响， 测定细胞内Ca2+和H+浓度。效果 SP对纯化的顶体和质膜的融合性的影响将 也被测试。 人类精子成为顶体反应的速率在以下方面不同： 男人有些男性的精子不能以正常的速度产生反应。这 行为与男性生育力低下相关，这表明， 不适当的顶体胞吐作用可能导致男性生育力低下。一 充分了解顶体胞吐作用的机制， 控制将提供新的见解，这类人类 生育力低下

The acrosome of a sperm must undergo exocytosis before the sperm fertilizes an egg. Freshly ejaculated mammalian sperm are not capable of exocytosis. They must first complete a poorly understood maturation process before they become acrosomally responsive. The long-term objective of this project is to understand the mechanisms by which exocytosis is controlled. Seminal plasma prevents sperm from becoming acrosomally responsive. The agents in seminal plasma that affect acrosomal responsiveness will be identified. This project will use seminal plasma and molecules isolated from it as tools to analyze the control of acrosomal responsiveness. Depending on how it is applied to sperm, seminal plasma can inhibit the development of acrosomal responsiveness, reverse acrosomal responsiveness, or augment acrosomal responsiveness. Because acrosomal exocytosis is triggered by an increased concentration of intracellular free Ca2+ and may require a rise in intracellular pH, the effect of seminal plasma on the intracellular concentrations of Ca2+ and H+ will be determined. The effect of SP on the fusibility of purified acrosomal and plasma membranes will also be tested. The rate at which human sperm become acrosomally responsive varies among men. Sperm of some men do not become responsive at a normal rate. This behavior is correlated with male subfertility, suggesting that inappropriate acrosomal exocytosis may contribute to male subfertility. A full understanding of the mechanisms by which acrosomal exocytosis is controlled will provide new insights into this class of human subfertility.