Abstract | STUDY DESIGN: Controlled, interventional, animal study. OBJECTIVE: SUMMARY OF BACKGROUND DATA: Application of nucleus pulposus on the nerve root induces immediate peripheral 5-HT production and the expression of 5-HT2A receptors in the adjacent DRG. However, the efficacy of a 5-HT2A receptor antagonist for pain relief in this situation and the mechanism remain unknown. METHODS: Autologous nucleus pulposus was applied to the left L5 nerve root of 91 adult female Sprague-Dawley rats. The selective 5-HT2A receptor antagonist sarpogrelate hydrochloride (SPG; 1 mg/kg or 10 mg/kg) or vehicle was administered orally once a day from 1 to 21 days postoperatively. Von Frey tests were used to test pain behavior before and after surgery. To assess the effect of SPG on endogenous 5-HT release surrounding the inflamed nerve root, we measured levels of 5-hydroxyindole acetic acid, a 5-HT metabolite, in plasma. Expression of 5-HT2A receptors in the left L5 DRG was examined with immunoblotting. RESULTS: The higher dose (10 mg/kg) of SPG significantly improved the mechanical withdrawal thresholds from 5 to 21 days after surgery compared with vehicle treatment. 5-hydroxyindole acetic acid in plasma was not significantly different among any groups at any time points. Both doses of SPG inhibited the expression of 5-HT2A receptors after surgery compared with vehicle treatment. CONCLUSION: LEVEL OF EVIDENCE: NA.
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Authors | Kinshi Kato, Miho Sekiguchi, Shin-ichi Kikuchi, Shin-ichi Konno |
Journal | Spine
(Spine (Phila Pa 1976))
Vol. 40
Issue 6
Pg. 357-62
(Mar 15 2015)
ISSN: 1528-1159 [Electronic] United States |
PMID | 25584948
(Publication Type: Journal Article)
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Chemical References |
- Receptor, Serotonin, 5-HT2A
- Serotonin 5-HT2 Receptor Antagonists
- Serotonin
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Topics |
- Animals
- Behavior, Animal
(drug effects)
- Disease Models, Animal
- Female
- Ganglia, Spinal
(drug effects, metabolism)
- Intervertebral Disc Displacement
(drug therapy, metabolism, physiopathology)
- Pain Management
(methods)
- Pain Measurement
(drug effects)
- Rats
- Rats, Sprague-Dawley
- Receptor, Serotonin, 5-HT2A
(analysis, biosynthesis)
- Serotonin
(analysis, blood, metabolism)
- Serotonin 5-HT2 Receptor Antagonists
(pharmacology)
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