Microdialysis Studies

微透析探头技术提供了进入组织间质的通道，用于可扩散组织成分的采样或生物活性物质的输送。然而，探针灌流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、灌注率和探针插入组织的创伤的复杂函数。正在对这些相关性进行研究，以提高该技术的数量有用性。大脑的应用正在与帕金森氏症、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。感兴趣的内源溶质包括多巴胺和喹啉酸。使用外源性物质的例子有齐多夫定(AZT)、乙醇和可卡因。数学模型被用来描述探针内和周围组织中的扩散和对流溶质传输。所需的探头物理性质的知识，例如探针膜的扩散和对流渗透率，可以在体外良好表征的条件下确定。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，以及探针灌流液浓度的测量。

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), ethanol and cocaine. 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.