Microdialysis Studies

微透析探针技术为可扩散组织成分的取样或生物活性物质的递送提供了进入组织微囊的途径。然而，探针灌注液浓度与其组织对应物的关系是溶质分子量、溶质物理化学性质、组织性质、探针膜性质、探针几何形状、灌注速率和探针插入组织的创伤的复杂函数。目前正在研究这些依赖性，以提高该技术的量化效用。在大脑中的应用正在与帕金森氏病，艾滋病，酗酒和滥用药物的研究有关。其他应用涉及各种正常组织和肿瘤。感兴趣的内源性溶质包括多巴胺和喹啉酸。使用的外源性物质的实例是齐多夫定（AZT）、顺铂和类似物、氟康唑、乙醇、可卡因和阿片类药物。数学建模用于描述探针内和周围组织中的扩散和对流溶质传输。所需的探针的物理性质的知识，如探针膜的扩散和对流渗透性，可以确定在良好的表征条件下在体外。动物（大鼠和灵长类动物）的验证实验包括定量放射自显影、组织学和探针周围组织的化学分析，以及探针灌注液浓度的测量。

Microdialysis probe technology provides access to tissue interstitium for either sampling of diffusible tissue constituents or delivery of bioactive substances. However, the relationship of the probe perfusate concentrations to their tissue counterparts is a complex function of solute molecular weight, solute physicochemical properties, tissue properties, probe membrane properties, probe geometry, perfusion rate, and the trauma of probe insertion into the tissue. These dependencies are being studied in order to improve the quantitative usefulness of the technology. Applications in the brain are being pursued in connection with Parkinson's disease, AIDS, alcoholism, and studies of drugs of abuse. Other applications involve various normal tissues and tumors. Endogenous solutes of interest include dopamine and quinolinic acid. Examples of exogenous substances employed are Zidovudine (AZT), cisplatin and analogs, fluconazole, ethanol, cocaine and opioids. Mathematical modeling is used to describe diffusive and convective solute transport within the probe and in surrounding tissue. Required knowledge of physical properties of the probes, such as diffusive and convective permeabilities of probe membranes, can be determined under well-characterized conditions in vitro. Validation experiments in animals (rats and primates) involve quantitative autoradiography, histology, and chemical assay of tissue surrounding the probe, as well as measurement of probe perfusate concentrations.