Effects of long-term sensory vs. sympathetic denervation on the distribution of calcitonin gene-related peptide and tyrosine hydroxylase immunoreactivities in the rat lung.

In this study the effect of long-term selective sensory vs. sympathetic denervation was examined in the rat lung. Immunoreactivities for calcitonin gene-related peptide (CGRP) on the one hand and tyrosine hydroxylase (TH) on the other, were used as indexes to assess the changes in the two nerve systems. Following long-term chemosympathectomy a marked increase of CGRP-immunoreactive nerve fibers was seen in the sections, while TH-immunoreactive nerve fibers appeared depleted. Inversely, long-term sensory denervation resulted in an increase of TH-immunoreactive nerve fibers with a sharp decrease of CGRP-immunostained fibers. These results suggest a peripheral interaction between these innervation systems in the lung, the mechanism of which has still to be elucidated.