Origin of the adrenergic nerve fibers in the subdiaphragmatic vagus in the dog.

The vagi at the subdiaphragmatic level were studied by the Hillarp-Falck technic in combination with a nerve crush procedure in three normal dogs and in eight dogs that had undergone previous surgical excision of the superior cervical ganglion and/or the stellate ganglia. Unilateral ganglionectomies were performed so that the contralateral vagus served as a control. Based on these results, it is concluded that: (1) the subdiaphragmatic canine vagus contains numerous adrenergic nerve fibers; (2) the main portion of these vagal adrenergic fibers arises from the stellate ganglia; and (3) removal of both the stellate and the superior cervical ganglia results in nearly complete adrenergic denervation of the abdominal vagus.