Increased density of perivascular adrenergic innervation in tibial and vagus nerves of spontaneously hypertensive rats.

Adrenergic innervation of epiperineurial arterioles and of the endoneurium of the tibial and vagus nerves of spontaneously hypertensive rats (SHR) and normotensive controls (WKY) was studied by glyoxylic acid-induced fluorescence and paraformaldehyde-induced fluorescence methods. Adrenergic perivascular innervation of epiperineurial arterioles in both nerves was denser in SHR than in controls. Mean density in the endoneurium also was higher in SHR in both nerve types. These results suggest that adrenergic perivascular innervation, which may influence nerve blood flow, becomes greater in density in peripheral nerves during chronic hypertension.