Origin of the calcitonin gene-related peptide-immunoreactive nerve fibers in the rat shoulder joint.
The rat shoulder joint capsule is innervated by thin sympathetic and sensory nerve fibers, most of which contain calcitonin gene-related peptide (CGRP). In order to establish the origin and distribution of CGRP-immunoreactive (IR) fibers, wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP) was injected into the shoulder joints of rats via a dorsal surgical approach. After WGA-HRP injection, the cervico-thoracic dorsal root ganglia (DRG) were removed and processed using both HRP histochemistry and CGRP immunohistochemistry. In the C4 to C7 DRG, small to medium-sized neurons (20-40 microns) were labeled by this combined method. The number and size of the labeled neurons were measured in the cervical 4th-7th DRG. The number of double-labeled neurons was one quarter of the total number of HRP-labeled neurons and 1/20 of the CGRP-IR neurons. Most of the double-labeled cells were located in the C6 ganglion, and the mean number of double-labeled neurons was 13 at this level. This distribution and function of the CGRP-IR fibers in the rat shoulder joint capsule are discussed.
Kobayashi
A
A
Department of Orthopedic Surgery, Fukushima Medical College, Japan.
Yoshida
N
N
Tonosaki
Y
Y
Kikuchi
S
S
Sugiura
Y
Y
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000032:analysis*; D005260:Female; D005727:Ganglia, Spinal / Q000737:chemistry / Q000166:cytology / Q000648:ultrastructure; D006735:Horseradish Peroxidase; D007150:Immunohistochemistry; D009412:Nerve Fibers / Q000737:chemistry* / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar; D012785:Shoulder Joint / Q000294:innervation*; D014909:Wheat Germ Agglutinins
D014909:Wheat Germ Agglutinins; D006735:Horseradish Peroxidase; D015740:Calcitonin Gene-Related Peptide