Substance-P-containing nerve fibers in the nasal mucosa.

Nerve fibers displaying SP immunoreactivity were detected in the nasal mucosa of several mammals. The fibers were seen around small blood vessels, seromucous glands, and beneath and sometimes within the surface epithelium. In the pterygopalatine ganglion and the trigeminal ganglion, known to innervate the nasal mucosa, SP-positive nerve cell bodies were seen. Sympathetic denervation with 6-hydroxydopamine (6-OHDA) or bilateral cervical sympathectomy did not visibly affect the distribution of SP fibers in the nasal mucosa in mice or rats. The findings are compatible with the view that the bulk of SP fibers to the nasal mucosa derive from the trigeminal ganglion with a possible contribution from the pterygopalatine ganglion.