Sympathetic and Sensory Innervations Are Heterogeneously Distributed in Relation to the Blood Vessels at the Extensor carpi radialis brevis Muscle Origin of Man

Abstract

By using immunohistochemistry and antibodies to a general nerve marker, protein gene product (PGP) 9.5, the overall innervation at the extensor carpi radialis brevis (ECRB) muscle origin was investigated in patients with tennis elbow and in healthy controls. The autonomic innervation was studied by using antibodies to neuropeptide Y (NPY), tyrosine hydroxylase (TH), and vasoactive intestinal peptide (VIP). The sensory innervation was visualized by using antibodies to substance P and calcitonin gene-related peptide. PGP 9.5 immunoreactions were detected in association with small blood vessels and arteries and within nerve bundles. There was, however, heterogeneity in the perivascular nerve fiber distribution since some blood vessels exhibited a high degree of PGP 9.5 innervation and some negligible or no such innervation at all. There was marked TH/NPY innervation in the walls of a subpopulation of the arteries, basically no VIP-containing nerves, and sensory innervation restricted to the small blood vessels. These observations show that the ECRB muscle origin is supplied with heterogeneously distributed sympathetic and sensory innervations and, furthermore, that there appears to be an imbalance between the vasoconstrictor and vasodilator innervations along the vascular tree in this region.

In vivo investigation of ECRB tendons with microdialysis technique--no signs of inflammation but high amounts of glutamate in tennis elbow

“…However, recent research has clarified the innervation at the ECRB muscle origin, and showed the presence of sensory nerve fibers (Ljung et al 1999a). Using immunohistochemistry and antibodies to the neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP), SP-and CGRP-like immunoreactivity at the muscle origin has been demonstrated (Ljung et al 1999b). It is known that SP and CGRP have afferent functions (transmitting nociceptive information to the spinal cord), but also efferent functions like involvement in vasodilatation and plasma extravasation (so-called neurogenic inflammation) (Wiesenfeld-Hallin and Xu 1993).…”

Treatment of Tendinopathy: What Works, What Does Not, and What is on the Horizon

“…The rationale behind using sclerotherapy in tendinopathy is based on the finding that there is a proliferation of small blood vessels in areas of tendinopathy. Nerve fibers appear to travel in close proximity to these areas of neovascularization [24,95,97]. It is possible these nerve fibers are the pain generators in tendinopathy.…”

Early nerve regeneration after Achilles tendon rupture — a prerequisite for healing? A study in the rat

“…As for tendons, we were recently able to demonstrate the presence of sensory and autonomic neuropeptides in normal Achilles tendon of the rat [1,2]. These neuropeptides have also been found in tissues from patients with lateral elbow tendinosis [24,25]. Calcitonin gene-related peptide (CGRP), representing the sensory nervous system, is known to act vasodilatory, to participate in the regulation of angiogenesis, proliferation of fibroblasts and synoviocytes [7,16,38] as well as synthesis of cytokines and growth factors [8,28].…”