Back to Search
Start Over
Participation of 5-hydroxytryptamine in pain-related behavior induced by nucleus pulposus applied on the nerve root in rats.
- Source :
-
Spine [Spine (Phila Pa 1976)] 2008 May 20; Vol. 33 (12), pp. 1330-6. - Publication Year :
- 2008
-
Abstract
- Study Design: The role of 5-hydroxytryptamine (5-HT) in sciatica in lumbar disc herniation (LDH) in rats was investigated.<br />Objective: We evaluated the effects of exogenous 5-HT applied on the nerve root on pain-related behavior, the release of endogenous 5-HT in plasma, and the expression of 5-HT2A receptors in dorsal root ganglion (DRG) in a rat LDH model.<br />Summary of Background Data: In previous studies, 5-HT2A receptor antagonists improved sciatica in patients with LDH and attenuated pain-related behavior induced by nucleus pulposus applied to the nerve root in rats.<br />Methods: Adult female Sprague-Dawley rats were divided into four experimental groups [control group; low-dose (10 microg) 5-HT-group; high-dose (30 microg) 5-HT-group; and autologous nucleus pulposus (NP) and saline group] and each drug was applied to the L5 nerve root. Von Frey tests were used for pain-behavior testing. To assess levels of endogenous 5-HT released in capillaries surrounding inflamed nerve roots, we measured 5-hydroxyindole acetic acid (5-HIAA), a metabolite of 5-HT. Expression of 5-HT2A receptors in the left L5 DRG was examined by immunohistochemical and immunoblotting analyses in the control and NP groups.<br />Results: Mechanical withdrawal thresholds of the high-dose 5-HT and the NP groups were significantly decreased after surgery compared with the control group and recovered after 14 days in the high-dose 5-HT group. 5-HIAA in plasma was increased by nucleus pulposus applied on the nerve root for 7 days after surgery. The expression of 5-HT2A receptors was enhanced in a time-dependent manner by nucleus pulposus.<br />Conclusion: Exogenous 5-HT to the nerve root induced pain-related behavior with short-lasting effects compared with the nucleus pulposus application. 5-HIAA content in plasma and expression of 5-HT2A receptors in DRG neurons increased early time points after the nucleus pulposus application. These results suggest that 5-HT plays a role in the early phase of the chemical pathogenesis of sciatica in LDH in rats.
- Subjects :
- Animals
Blotting, Western
Chromatography, High Pressure Liquid
Disease Models, Animal
Female
Ganglia, Spinal metabolism
Hydroxyindoleacetic Acid blood
Immunohistochemistry
Intervertebral Disc surgery
Intervertebral Disc Displacement metabolism
Lumbar Vertebrae surgery
Pain Measurement
Pain Threshold
Rats
Rats, Sprague-Dawley
Receptor, Serotonin, 5-HT2A metabolism
Sciatica etiology
Serotonin administration & dosage
Serotonin blood
Time Factors
Up-Regulation
Behavior, Animal
Intervertebral Disc metabolism
Intervertebral Disc Displacement complications
Lumbar Vertebrae metabolism
Sciatica metabolism
Serotonin metabolism
Spinal Nerve Roots metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1528-1159
- Volume :
- 33
- Issue :
- 12
- Database :
- MEDLINE
- Journal :
- Spine
- Publication Type :
- Academic Journal
- Accession number :
- 18496345
- Full Text :
- https://doi.org/10.1097/BRS.0b013e318173298b