ABSTRACT
Avian pancreatic polypeptide (APP)-like immunoreactivity (Li) was also observed in adrenergic nerves, mainly around arteries. Subsequently, it became clear that the APP-like substance in perivascular nerves was most likely identical to the structurally related peptide neuropeptide Y (NPY), a 36-amino-acid peptide originally isolated from porcine brain. The sympathetic nerve supply is of importance both for nutritive blood flow and tone of the large venous sinusoids and thereby for nasal airway resistance. Sympathetic stimulation using a high frequency is associated with profound vascular effects and increased overflow of NPY Li into the nasal venous effluent, suggesting release. Since large nasal and long-lasting vasoconstrictor effects to sympathetic stimulation remain after reserpine, there is suggestive evidence for a role of a nonadrenergic transmitter like NPY both in the vascular control of the nasal mucosa. The relative effects of NPY at the prejunctional level on sympathetic, parasympathetic, and sensory nerves have to be established.
