Labeling of calcitonin gene-related peptide and substance P increases in subnucleus caudalis of rabbit during maxillary sinusitis.

Calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) and substance P-like immunoreactivity (SP-LI) were evaluated in subnucleus caudalis following induction of sinusitis. Three days after induction, intensity of labeling for CGRP-LI and SP-LI increased in ipsilateral subnucleus caudalis. Labeling for CGRP-LI and SP-LI appeared normal at later time points (20 and 28 days). Early changes in these neuropeptides may contribute to the inflammatory process and painful symptoms accompanying sinusitis.