Abstract
Background: Chronic discogenic pain includes degeneration-driven changes under the mechanical macroenvironment of an internal disc, which leads to the progressive changes of biochemical microenvironment that induce abnormal ingrowth of the nociceptor. The propriety of the animal model reflecting the pathologic natural history has not been assessed. Objectives: This study investigated the biochemical evidence of chronic discogenic pain by employing a discogenic pain animal model induced by shear force. Study Design: Animal study utilizing rats in vivo model of a shear force device. Methods: Fifteen rats were divided into 3 groups (n = 5/group) according to the period for which sustained dorsoventral shear force was applied (1 week or 2 weeks); the control group received the spinous attachment unit, without a spring. Pain data were collected using von Frey hairs on the hind paws. Growth factor and cytokine abundance was analyzed in the dorsal root ganglion (DRG) and plasma. Results: After the shear force devices were installed, the significant variables were found to markedly increase in the DRG tissues of the 2-week group; however, they were not altered in the 1-week group. Specifically, interleukin (IL)-6, neurogrowth factor (NGF), transforming growth factor (TGF)-α, platelet-derived growth factor (PDGF)-β, and vascular endothelial growth factor (VEGF) were increased. Meanwhile, the plasma levels of tumor necrosis factor-α, IL-1β, IL-5, IL-6, IL-12, and NGF were increased in the 1-week group; whereas, TGF-α, PDGF-β, and VEGF were increased in the 2-week group. Limitations: The limitations include the general limitations of quadrupedal animals, the poor precision and flexural deformation of shear force devices, inaccuracies regarding the evaluation of histological denaturation, and short intervention and observational periods. Conclusions: This animal model effectively generated biochemical responses to shear loading with evidence of neurological changes induced without direct macrodamage to the outer annulus fibrosus. Chemical internals were induced by mechanical externals among the contributing factors of chronic discogenic pain.
Original language | English |
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Pages (from-to) | E181-E189 |
Journal | Pain Physician |
Volume | 26 |
Issue number | 3 |
Publication status | Published - 2023 |
Bibliographical note
Funding Information:Address Correspondence: Nackhwan Kim, MD, PhD Department of Physical Medicine and Rehabilitation, Korea University Guro Hospital 148, Gurodong-ro, Guro-gu Seoul, 08308, Republic of Korea E-mail: [email protected] Disclaimer: This work was supported by the Korea Medical Device Development Fund grant funded by the Korea government (the Ministry of Science and ICT, the Ministry of Trade, Industry and Energy, the Ministry of Health & Welfare, the Ministry of Food and Drug Safety) (Project Number: 1711138408, KMDF_ PR_20200901_0189), and by a Korea University Ansan Hospital Grant (O1903511).
Publisher Copyright:
© 2023, American Society of Interventional Pain Physicians. All rights reserved.
Keywords
- Discogenic pain
- animal model
- dorsal root ganglion
- growth factor
- interleukin
- intervertebral discs
- low back pain
- shear force
ASJC Scopus subject areas
- Anesthesiology and Pain Medicine