INTRACELLULAR MECHANICS OF INTESTINAL MUCUS SECRETION

该项目的目标是提供深入了解“粘液分泌”， 囊性纤维化（CF）的“缺陷”，提供基线信息， 正常杯状细胞的肠粘液分泌。 虽然CF 肠粘液可能异常粘稠，没有特异性异常， 在CF组织中发现了这种改变，以解释这种改变的理化性质 行为 本研究将从几个方面探讨这一问题。 不同的方面。 首先，将继续进行研究， 其加速或抑制肠中的正常分泌速率。 这 将通过放射自显影术和灵敏的酶免疫测定法进行监测 (EIA)老鼠肠道粘液的样本 第二，细胞内转运 在各种不同的时间内，将通过放射自显影术监测颗粒。 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;和4） 慢性加速分泌 颗粒的作用机制 隔离和运输将通过一个全面的调查 分析上述每种分泌型中杯状细胞细胞骨架 采用超微结构、冷冻断裂和免疫细胞化学 技术. 在实验性分泌状态下， 也可以通过超微结构和冷冻断裂方法进行监测。 最后，将通过实验诱导慢性高分泌状态 使用胆碱能药物或管腔刺激物。 的改变 通过放射自显影术监测颗粒运动模式， 将测定肠细胞群的改变。 的 该项目的最终目标是确定正常反应， 肠杯状细胞分泌实验条件。 只有这样 可以计划利用正常人和CF组织的有意义的实验， 并确定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.