MEDULLARY CHEMORECEPTOR PHYSIOLOGY

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。 氢离子与 延髓化学感受器组织的活动和膈神经活动将 在麻醉的大鼠和猫中，通过使用pH值测量组织pH值进行研究。 微电极监测动脉PCO 2和PO 2的变化。 的可能性 将测试高流量CSF灌注期间的经小动脉CO2交换 通过测量组织pH值，同时改变动脉和CSF灌注液PCO 2， 相同的和相反的方向。 通过测量局部组织灌注 带有伺服控制的温度探头，同时测量 组织pH，化学感受器组织中血流对 PO_2和PCO_2的变化及其与组织氢离子活性的关系 将被研究。 载体介导的交换对组织pH的影响 将通过测量组织pH值响应来研究HCO 3-跨细胞 在HCO 3药物阻断前后改变动脉PCO 2 载体 Yamamoto关于二氧化碳生成的假设 呼吸神经元活动和随后的化学感受器刺激将 通过在刺激颈动脉期间测量化学感受器pH来测试 窦神经 这些研究应该提供拒绝或接受的证据 化学感受器机制的假说是至关重要的。

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.