CARBON DIOXIDE TRANSPORT AND CHEMOSENSITIVITY

动脉血中二氧化碳浓度的增加导致 疾病或环境的改变对呼吸有深远的影响。它 被认为主要负责脑干化学感受器 由反应决定的氢离子变化的刺激 二氧化碳与组织中的水以及其他强烈的 离解离子。这项研究是基于这样一种假设：载体 离子跨细胞膜的介导运输是 测定对大脑中呼吸化学感受器的刺激 茎。我们建议通过实验来评估这一假设 麻醉的猫和兔子，测量对 急性呼吸性酸中毒。载体介导的抑制剂 钠/钾偶联氯化物交换将由 脑干脑脊液间隙的灌流 大池子。区域和细胞类型的精确定位 离子交换抑制剂将通过定量制备 免疫荧光显微镜。离子转运抑制对血管紧张素转换酶活性的影响 细胞外液的pH值将在细胞外的位置进行测定 化学感受器及其对细胞内元素浓度的影响 通过电子探针微区分析。这项工作的目标是 对髓质形成的化学过程的理解 化学感受器在酸碱呼吸控制中的作用 由急性或慢性呼吸衰竭引起的紊乱。

An increase in the carbon dioxide concentration in arterial blood caused by disease or altered environment has a profound effect on breathing. It is thought that the brain stem chemoreceptors primarily responsible are stimulated by hydrogen ion changes which are determined by the reaction of CO2 with water in the tissue and by the activities of other strongly dissociated ions. This study is based on the hypothesis that carrier mediated transport of ions across cell membranes is a cardinal step in determining the stimulus to the respiratory chemoreceptors in the brain stem. We propose to evaluate this hypothesis by experiments in anesthetized cats and rabbits, measuring the ventilatory response to acute respiratory acidosis. Inhibitors of carrier mediated sodium/potassium coupled chloride exchange will be administered by perfusing the cerebrospinal fluid space of the brain stem via the cisterna magna. Precise localization of region and cell type for the inhibitors of ion exchange will be made by quantitative immunofluorescence microscopy. The effect of ion transport inhibition on extracellular fluid pH will be determined at the site of the chemoreceptors and the effect on intracellular elemental concentrations by electron probe microanalysis. The objective of this work is an understanding of the chemical processes responsible for the medullary chemoreceptors role in controlling breathing during acid-base disturbances which result from acute or chronic respiratory failure.