IN VIVO INVESTIGATIONS USING MICRODIALYSIS SAMPLING

描述（由申请人提供）：本项目的主要目标是发展微透析取样方法和相关的分析技术来研究胃溃疡。这些技术将用于幽门螺杆菌和非甾体抗炎药（NSAIDs）引起的溃疡的比较研究。该系统的目标分析物包括组胺、碳酸氢盐/pH、n -乙酰神经氨酸（NANA）、一氧化氮（NO）和前列腺素。这些化合物在溃疡形成中起直接作用，起到保护作用，或者是组织状态的生物标志物。微透析取样将成为这些研究的基础，并提供以前无法用于研究溃疡和健康胃组织的能力。以前，在每个时间点必须牺牲几只动物来收集组织进行检查，微透析采样提供了在较长时间内从每只实验动物的胃组织连续采样。此外，通过在胃的多个点植入微透析探针，可以在同一只动物身上研究健康组织和溃疡组织。该项目将分三个阶段进行。在第一阶段，细胞培养模型将在体外使用。用这种方法可以分离研究特定的细胞系。在本项目的第二阶段，将使用切除的胃组织作为模型系统。乙醇、乙酸、吲哚美辛和幽门螺旋杆菌均可诱发胃溃疡。然后将胃切除并沿着更大的曲率打开，以便使用微透析取样进行体外研究。然后将微透析探针放入溃疡和健康组织中。该项目的最后阶段将使用微透析取样检查健康和溃烂的胃组织。

DESCRIPTION (provided by applicant): The primary goal of this project is to develop microdialysis sampling methods and associated analytical techniques to study gastric ulcers. These techniques will then be used in a comparative study of ulcers induced by Heliobacter pylori and by nonsteroidal anti-inflammatory drugs (NSAIDs). The target analytes in this system include histamine, bicarbonate/pH, N-acetylneuraminic acid (NANA), nitric oxide (NO) and prostaglandins. These compounds play a direct role in ulcer formation, serve a protective role, or are biomarkers for tissue status. Microdialysis sampling will form the basis for these studies and provide capabilities not previously available for studying ulcerated and healthy gastric tissue. Where previously, several animals had to be sacrificed to collect tissue for examination at each time point, microdialysis sampling provides for continuous sampling from the gastric tissue of each experimental animal over extended times. In addition, by implanting microdialysis probes at more than one point in the stomach, both healthy and ulcerated tissue can be studied in the same animal. The project will proceed in three stages. In the first stage, cell culture models will be utilized in vitro. In this manner specific cells lines can be studied in isolation. In the second stage of this project, excised stomach tissue will be used as a model system. Gastric ulcers will be induced by ethanol, acetic acid, indomethacin, and H. pylori. The stomach will then be excised and opened along the greater curvature for in vitro investigation using microdialysis sampling. Microdialysis probes will then be placed into ulcerated and healthy tissue. The final stage of this project will be to examine the healthy and ulcerated stomach tissue in vivo using microdialysis sampling. These methods will then be used in a comparative study of ulcers induced by H. pylori and NSAIDs. In particular, the role of mucus disruption versus acid efflux will be investigated. By continually monitoring the rate of mucus secretion versus acid secretion as a function time, the relative importance of these to processes in ulceration by the various inducers can be determined. This knowledge will aid in the development of advanced preventative and remedial treatments for ulcers resulting from different inducing agents.