CONTROL OF CELLS OF THE REPRODUCTIVE AXIS

本项目关注生殖轴细胞的信号机制。将在雄性小鼠生殖系细胞和附睾精子以及雄性大鼠垂体促性腺激素中研究电兴奋性和大鼠细胞内信号传导。利用膜片钳和光学指示器对单个活细胞的生理进行研究。指导性假设是膜电位，细胞内Ca2+和环AMP是控制生殖步骤的关键细胞信号。精子和精子的离子通道将通过膜片钳和免疫细胞化学进行鉴定，特别关注电压门控的Ca2+通道。在精子和精细胞中，比较碳酸氢盐对环AMP、蛋白质磷酸化、运动和离子通道功能的作用。调节Ca2+从精子和精子细胞质清除的机制将被确定。在促性腺激素中，免疫细胞化学实验将确定IP3对Ca2+的摄取和缓冲，以允许在促性腺激素释放激素诱导的Ca2+振荡期间制定和测试细胞Ca2+动力学模型。这些研究将确定未来男性避孕药的潜在目标。

This project concerns signaling mechanisms in cells of the reproductive axis. Electrical excitability and rat intracellular signaling will be studied in male mouse germ-line cells and epididymal spermatozoa and in male rat pituitary gonadotropes. The physiology of single living cells will be studied by patch clamp and optical indicators. The guiding hypotheses are that membrane potential, intracellular Ca2+, and cyclic AMP are key cellular signals that control steps in reproduction. The ion channels of spermatids and sperm will be identified by patch clamp and immunocytochemistry, with special attention to voltage-gated Ca2+ channels. In sperm and spermatids the actions of bicarbonate on cyclic AMP, protein phosphorylation, motility and ion channel function will be compared. Mechanisms regulating Ca2+ clearance from sperm and spermatid cytoplasm will be identified. In gonadotropes, immunocytochemical experiments will identify the IP3 uptake and buffering of Ca2+ to permit formulation and test of kinetic models for cellular Ca2+ dynamics during the Ca2+ oscillations induced by gonadotropin releasing hormone. These studies will identify potential targets for future male contraceptives.