CO2 TRANSPORT AND MEDULLARY CHEMORECEPTOR PHYSIOLOGY

二氧化碳传输和髓质化学感受器生理学

• 批准号: 3073666
• 负责人: JEROME M ADAMS
• 金额: $ 5.14万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 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/3073666
• 关键词: acidity /alkalinity; anions; arterioles; carbon dioxide transport; carbonate dehydratase; chemoreceptors; dyes; homeostasis; mathematical model; microelectrodes; neurophysiology; perfusion; phrenic nerve; pulmonary respiration; vascular endothelium permeability

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.

合理治疗呼吸道疾病，尤其是急性呼吸道疾病 失败和二氧化碳潴留的慢性疾病，是基于 了解二氧化碳对呼吸的控制。 延髓化学感受器 在调节呼吸方面起着至关重要的作用， 其活动尚未确定。 CO2水合的催化作用 产生氢离子和跨细胞阴离子（HCO 3）交换 （缓冲这一过程）将在麻醉大鼠中进行研究， 通过CSF灌注将这些过程的阻断剂施用到脑内。 枕大池和测量对CO2的排泄反应。 的关系 髓质化学感受器组织中的氢离子活性与 将通过测量在麻醉的大鼠和猫中的通气量来研究 组织pH值，pH微电极插入组织和膈神经 在动脉PCO2和PO2的瞬时变化期间的活性。 通过测量 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， 化学感受器组织对PO2和PCO2变化的反应及其与组织的关系 将研究氢离子活性。 经动脉的可能性 将通过测量组织pH值，同时改变动脉 和CSF以相同和相反的方向灌注PCO2。 化学感受器组织中CO2运输的理论描述将集中在 对阴离子交换、缓冲和小动脉交换的影响。 这些研究应 提供拒绝或接受化学感受器机制假设的证据 这是至关重要的。