INTRACELLULAR MECHANICS OF INTESTINAL MUCUS SECRETION

这个项目的目标是提供对“粘液分泌”的洞察 囊性纤维化(CF)的“缺陷”通过提供关于 正常杯状细胞的肠道粘液分泌。尽管配置 肠道粘液可能有异常粘性，无特异性异常。 已在CF组织中发现，以解释这种改变的物理化学 行为。本研究将从以下几个方面探讨这个问题 不同的方面。首先，将继续进行研究以确定这些病原体 可加速或抑制肠道的正常分泌速度。这 将通过放射自显影和灵敏的酶免疫测定法进行监测 (EIA)用于大鼠肠粘液。其次，细胞内转运 颗粒将通过放射自显影在各种不同的 实验性分泌状态，包括：1)基线分泌；2) 加速分泌；3)从加速分泌中恢复；4) 慢性加速分泌。颗粒形成的机制 隔离和运输将通过全面的 上述各分泌物中杯状细胞骨架的分析 使用超微结构、冷冻骨折和免疫细胞化学的状态 技巧。实验性分泌状态下的细胞膜改变将 也可以通过超微结构和冷冻断裂法进行监测。 最后，将在实验中诱导出一种慢性过度分泌状态 使用胆碱能药物或鲁米那刺激物。中的更改 颗粒的运动模式将通过放射自显影和 肠道细胞数量的变化将被确定。这个 该项目的最终目标是确定以下对象的正常反应 肠道杯状细胞对实验分泌条件的调节。只有在那时 能否计划利用正常人和CF组织进行有意义的实验， 并确定了CF组织中分泌过程的异常。

The goal of this project is to provide insight into the "mucous secretory defect" in cystic fibrosis (CF) by providing baseline information on intestinal mucus secretion from normal goblet cells. Although CF intestinal mucus may be abnormally viscous, no specific abnormality has been identified in CF tissue to account for this altered physiochemical behavior. The present study will approach the problem from several different aspects. First, studies will be continued to identify the agents which accelerate or inhibit normal secretory rates in the intestine. This will be monitored by autoradiography and by a sensitive enzymeimmunoassay (EIA) for rat intestinal mucus. Secondly, the intracellular transport of granules will be monitored by autoradiography during a variety of experimental secretory states, including: 1) baseline secretion; 2) accelerated secretion; 3) recovery from accelerated secretion; and 4) chronic accelerated secretion. The mechanisms by which granules are segregated and transported will be investigated through a comprehensive analysis of the goblet cell cytoskeleton in each of the above secretory states using ultrastructural, freeze fracture and immunocytochemical techniques. Membrane alterations during experimental secretory states will also be monitored by ultrastructural and freeze fracture methodologies. Finally, a chronic hypersecretory state will be experimentally induced using either cholinergic agents or luminal irritants. Alterations in granule movement patterns will be monitored by autoradiography and alterations in intestinal cell populations will be determined. The ultimate goal of this project is to identify the normal responses of intestinal goblet cells to experimental secretory conditions. Only then can meaningful experiments utilizing normal human and CF tissue be planned, and abnormalities in the secretory process in CF tissue be determined.