Trophic effects of peripheral adrenergic nerves on vascular structure

In the rat and rabbit, evidence for a trophic action of sympathetic nerves on vascular pattern and structure has been reviewed. Effects have been identified by denervation and reinnervation techniques in blood vessels of different size from different regions. Following denervation, increased nonspecific sensitivity to constrictor agents occurs at all ages. In contrast, sympathetic trophic effects on muscle mass, extracellular artery components, and vessel number in the microvasculature were observed predominantly during growth. The mechanism of this action is not known, but the central ear artery in the rabbit was associated with nerve impulses.