PULMONARY VASOMOTOR FIBRES IN THE CERVICAL VAGOSYMPATHETIC NERVE OF THE DOG

In perfused lung preparations under conditions which exclude passive effects due to bronchomotor responses: 1. Electrical stimulation of the separated cervical vagus or cervical sympathetic gives rise to pulmonary vasomotor responses. The vagosympathetic contains preganglionic fibres, some of which have their cell stations in the middle cervical ganglion. Others are postganglionic. 2. Electrical stimulation or the application of nicotine to the superior cervical ganglion or the nodose ganglion causes pulmonary vasomotor responses. 3. In atropinized perfused preparations the response to cervical vagosympathetic stimulation is predominantly pulmonary vasopressor, in non-atropinized preparations predominantly vasodepressor.