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Updated: May 22, 2026
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Rat Model of Adhesive Capsulitis of the Shoulder
Published on: September 28, 2018
Sensory innervation of rat contracture shoulder model
Nobuyasu Ochiai1, Seiji Ohtori, Tomonori Kenmoku
1Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan. nobunobu1215@yahoo.co.jp
Journal of Shoulder and Elbow Surgery
|May 22, 2012
Summary
Frozen shoulder pain may stem from increased calcitonin gene-related peptide (CGRP) in dorsal root ganglion (DRG) neurons. This study established a rat model to investigate shoulder contracture and CGRP expression, revealing a potential pain mechanism.
Area of Science:
- Orthopedics
- Neuroscience
- Pain Research
Background:
- Limited understanding of pain mechanisms in frozen shoulder.
- Need to investigate the innervation of the glenohumeral (GH) joint and subacromial bursa (SAB).
Purpose of the Study:
- Establish a rat model of shoulder contracture.
- Clarify the innervation pattern of the GH joint and SAB in relation to pain.
Main Methods:
- Created rat contracture models and confirmed via X-ray.
- Used neurotracers (Fluoro-Gold and DiI) for GH joint and SAB labeling.
- Performed immunohistochemistry for calcitonin gene-related peptide (CGRP) in dorsal root ganglion (DRG) neurons.
Main Results:
- Contracture models showed significantly decreased shoulder range of motion.
- A higher percentage of CGRP-immunoreactive (CGRP-ir) DRG neurons were observed in the contracture group for both GH joint and SAB.
Conclusions:
- Up-regulation of CGRP expression in DRG neurons may induce pain sensation in rat shoulder contracture.
- Provides insight into the neurobiological basis of frozen shoulder pain.
