Adrenergic innervation of the Eustachian tube. Histochemical and electron-microscopic study

The presence of adrenergic nerves in the Eustachian tubes of guinea pigs was observed using the Falck-Hillarp fluorescence method. Abundant adrenergic nerve are forming networks around blood vessels in all tubal regions. Adrenergic fibers also surround the tubal glands. The precise locations of adrenergic nerve terminals in the tube were demonstrated by electron microscopy following application of a false transmitter. Adrenergic nerve terminals were found in abundance just beneath the smooth muscle layer of the arteries in each part of the tube and close to the myoepithelial cells of the tubal gland.