CO2 TRANSPORT AND MEDULLARY CHEMORECEPTOR PHYSIOLOGY

二氧化碳传输和髓质化学感受器生理学

基本信息

批准号：
3073668
负责人：
JEROME M ADAMS
金额：
$ 5.32万
依托单位：
UNIVERSITY OF VIRGINIA
依托单位国家：
美国
项目类别：
财政年份：
1983
资助国家：
美国
起止时间：
1983-09-01 至 1988-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/3073668
关键词：
acidity /alkalinity anions arterioles carbon dioxide transport carbonate dehydratase chemoreceptors dyes homeostasis mathematical model medulla oblongata microelectrodes neurophysiology perfusion phrenic nerve pulmonary respiration respiration regulatory center vascular endothelium permeability

项目摘要

Rational treatment of respiratory disease, especially acute respiratory failure and CO2 retention in chronic diseases, is based on the understanding of CO2 control of breathing. The medullary chemoreceptors play a crucial role in regulating breathing but the mechanisms governing their activity are not established. The role of catalysis of CO2 hydration in producing hydrogen ions and of anion (HCO3) exchange across cells (buffering this process) will be studied in anesthetized rats by administering blocking agents of these processes via CSF perfusion into the cisterna magna and measuring the ventilatory response to CO2. The relation between hydrogen ion activity in medullary chemoreceptor tissue and ventilation will be studied in anesthetized rats and cats by measuring tissue pH with a pH microelectrode inserted in the tissue and phrenic nerve activity during transient changes of arterial PCO2 and PO2. By measuring local tissue perfusion with a servo controlled temperature probe, with simultaneous measure of tissue pH, the response of blood flow in the chemoreceptor tissue to changes of PO2 and PCO2 and its relation to tissue hydrogen ion activity will be studied. The possibility of trans-arteriolar CO2 exchange will be tested by measuring tissue pH while changing arterial and CSF superfusate PCO2 in the same and in opposing directions. Theoretical description of CO2 transport in chemoreceptor tissue will focus on anion exchange, buffering and arteriolar exchange. These studies should provide evidence to reject or accept hypotheses of chemoreceptor mechanisms which are of cardinal importance.

合理治疗呼吸系统疾病，特别是急性呼吸道疾病慢性疾病中的衰竭和二氧化碳潴留是基于了解二氧化碳对呼吸的控制。髓质化学感受器在调节呼吸方面发挥着至关重要的作用，但控制机制他们的活动尚未确定。 CO2水化的催化作用产生氢离子和阴离子 (HCO3) 在细胞间交换（缓冲这个过程）将在麻醉大鼠中进行研究通过脑脊液灌注将这些过程的阻断剂施用到小脑池并测量对 CO2 的通气反应。关系髓质化学感受器组织中的氢离子活性与将通过测量麻醉大鼠和猫来研究通气使用插入组织和膈神经的 pH 微电极测量组织 pH 值动脉 PCO2 和 PO2 瞬时变化期间的活动。通过测量使用伺服控制温度探头进行局部组织灌注，同时测量组织 pH 值、血流反应化学感受器组织对PO2和PCO2变化的影响及其与组织的关系将研究氢离子活性。经小动脉的可能性通过在改变动脉的同时测量组织 pH 值来测试二氧化碳交换和CSF以相同和相反的方向过度融合PCO2。化学感受器组织中二氧化碳运输的理论描述将集中于阴离子交换、缓冲和小动脉交换。这些研究应该提供证据来拒绝或接受化学感受器机制的假设这些都是至关重要的。