Changes in activity of vagal bronchopulmonary C fibres by chemical and physical stimuli in the cat.

摘要: 1. In eighteen anaesthetized cats, action potentials in non-myelinated vagal afferent neurones were recorded the nodose ganglion by means of extracellular micro-electrodes. 2. The pulmonary or bronchial origin these C fibres was assessed closed chest preparations injecting phenyl diguanide into either right atrium ascending aorta (bronchial circulation). This confirmed two animals local mechanical stimulation. 3. Eighty per cent bronchopulmonary increased their discharge frequency when end-tidal CO2 concentration (FA,CO2) from 0.02 to 0.10. Most endings showed a maximal response FA,CO2 reached 0.04. For others further increase occurred 0.08-0.10. Continuous measurement fibre indicated that they detected preferentially changes inspired content, but adapted high level maintained. Their activation hypercapnia followed an lung resistance. 4. Lowering O2 content gas had no effect on spontaneous activity endings. 5. When stroke volume pump doubled, decreased intact preparations. Inflation lungs opposite after opened. both cases hyperdeflation potent stimulus receptors. 6. tracheotomized tracheal temperature 28-29 degrees C. normal thermal conditions restored lumen (33-34 C) some greatly increased. 7. It is concluded most chemical and physical physiological lungs. appears alveolar constitute usual for fibres.