Innervation of the feline eustachian tube.

The distribution of adrenergic, cholinergic and peptidergic nerves in the feline eustachian tube was studied using histochemical techniques. Adrenergic, acetylcholinesterase-positive and vasoactive intestinal polypeptide immunoreactive nerves were numerous in the tubal wall. All three types of nerve fibers occurred in the subepithelial layer, around small blood vessels and around the acini of seromucous glands. No nerves displaying substance P or enkephalin immunoreactivity were observed.