REGIONAL BRAIN METABOLISM IN HEPATIC COMA

大脑功能和意识水平发生变化 在某些代谢性疾病中循环发生变化 底物和激素影响细胞的合成和周转 脑神经递质。其病理生理机制 对这些代谢中的大脑功能障碍负责 脑病仍有待澄清。已经有几个 近年来的重要技术进步将使 这些疾病的研究取得了进一步的进展。当前 代谢性脑病的病因假说有 倾向于只关注疾病的个别方面。但是 代谢性脑病的多因素特性表明 阐明其病因的最有效的方法将是 综合已描述的各种异常情况。 神经递质代谢改变与脑出血的关系 分布，受体密度和分布，蛋白质合成， 和大脑功能，在疾病的不同阶段可能 揭示了脑病发展的关键步骤 在孤立的单变量研究中可能仍然模糊不清 时间点。因此，这项提案的目标将是 重点抓好以下几个方面的工作： 生化、生理和结构变化 在新陈代谢中引起意识变化的重要因素 疾病，然后确定任何病因 常见于各种代谢性脑病(例如，肝脏， 尿毒症和糖尿病)。 将研究门体分流引起的脑病 第一。神经递质及其受体的区域定位 新陈代谢与新陈代谢的功能阶段有关 脑病。地区葡萄糖使用量将通过以下方式衡量 定量放射自显影及其作为脑功能指标的应用 功能。脑内主要神经递质和脑组织的局部含量 它们的代谢物将通过高效液体进行测定 层析法。他们的受体的分布将被评估 通过定量放射自显影。一种测量电磁场强度的方法 将制定区域氨代谢率和 已验证。血液和大脑中的氨基酸图谱，这可能 影响神经递质代谢，将被测量 同时。随后，研究将扩展到以下模型 尿毒症和糖尿病脑病。

Alterations in cerebral function and levels of consciousness occur in certain metabolic diseases where changes in circulating substrates and hormones influence the synthesis and turnover of brain neurotransmitters. The pathophysiologic mechanisms responsible for cerebral dysfunction in these metabolic encephalopathies remain to be clarified. There have been several important technical advances in recent years which will permit further progress in the study of these diseases. Current hypotheses of the etiology of metabolic encephalopathy have tended to focus only on isolated facets of the disease. But the multifactorial nature of metabolic encephalopathy suggests that the most productive approach to elucidating its etiology will be to integrate the various abnormalities which have been described. Correlation of alterations in neurotransmitter metabolism and distribution, receptor density and distribution, protein synthesis, and cerebral function, at different stages of the disease may reveal crucial steps in the development of encephalopathy that might remain obscure in studies of single variables at isolated time points. Accordingly, the goals of this proposal will emphasize the following aspects: the identification of those biochemical, physiologic and structural changes which are important in causing alterations in consciousness in metabolic disease, followed by the determination of any etiologic factors common to various metabolic encephalopathies (e.g., hepatic, uremic and diabetic). Encephalopathy caused by portal-systemic shunting will be studied first. Regional localization of neurotransmitters and their metabolism will be related to the functional stages of metabolic encephalopathy. Regional glucose use will be measured by quantitative autoradiography and used as an index of cerebral function. Regional brain content of major neurotransmitters and their metabolites will be determined by high performance liquid chromatography. Distribution of their receptors will be evaluated by quantitative autoradiography. A method for measuring the regional rate of ammonia metabolism will be developed and validated. Amino acid profiles in blood and brain, which may effect neurotransmitter metabolism, will be measured concurrently. Subsequently studies will be extended to models of uremic and diabetic encephalopathy.