MEDULLARY CHEMORECEPTOR PHYSIOLOGY

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滞留是基于 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，但 他们的活动尚未确定。氢离子之间的关系 延髓化学感受器组织的活动和膈神经的活动将 在麻醉的大鼠和猫身上进行研究，用pH测量组织的pH 微电极在动脉血二氧化碳分压和氧分压变化过程中的作用。是否有可能 将测试高流量脑脊液灌流时通过动脉的二氧化碳交换 通过改变动脉和脑脊液灌流PCO2的同时测量组织pH 是相同的，但方向相反。通过测量局部组织灌注量 带有伺服控制的温度探头，可同时测量 组织pH，化学感受器组织中的血流对 氧分压和二氧化碳分压的变化及其与组织氢离子活性的关系 将会被研究。载体介导的交换对组织pH的影响 将通过测量组织pH响应来研究HCO3跨细胞 HCO3药物阻断前后动脉血二氧化碳分压的变化 承运人。山本关于二氧化碳产生的假说 呼吸神经元活性和随后的化学感受器刺激将 通过测量刺激颈动脉时的化学感受器pH进行测试 鼻窦神经。这些研究应该提供证据来拒绝或接受 化学感受器机制假说是至关重要的。

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 relation between hydrogen ion activity in medullary chemoreceptor tissue and phrenic nerve activity will be studied in anesthetized rats and cats by measuring tissue pH with a pH microelectrode during changes of arterial PCO2 and PO2. The possibility of trans-arteriolar CO2 exchange during high flow CSF perfusion will be tested by measuring tissue pH while changing arterial and CSF perfusate PCO2 in the same and in opposing directions. 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 effect on tissue pH of the carrier mediated exchange of HCO3- across cells will be studied by measuring tissue pH response to altering arterial PCO2 before and after pharmacologic block of the HCO3 carrier. Yamamoto's hypotheses concerning the generation of CO2 by respiratory neuron activity and consequent chemoreceptor stimulation will be tested by measuring chemoreceptor pH during stimulation of the carotid sinus nerves. These studies should provide evidence to reject or accept hypotheses of chemoreceptor mechanisms which are of cardinal importance.