Roles of Adenosine and Serotonin Receptors on the Antinociception of Sildenafil in the Spinal Cord of Rats.
10.3349/ymj.2010.51.6.960
- Author:
Hyung Gon LEE
1
;
Woong Mo KIM
;
Cheon Hee PARK
;
Myung Ha YOON
Author Information
1. Department of Anesthesiology and Pain Medicine, Chonnam National University Medical School, Gwangju, Korea. mhyoon@chonnam.ac.kr
- Publication Type:Original Article
- Keywords:
Adenosine;
antinociception;
serotonin;
sildenafil;
spinal cord
- MeSH:
Adenosine/metabolism;
Analgesics/*therapeutic use;
Animals;
Cyclic GMP/metabolism;
Dihydroergocristine/pharmacology;
Injections, Spinal;
Male;
Pain/*drug therapy;
Piperazines/*pharmacology;
Purines/pharmacology;
Rats;
Rats, Sprague-Dawley;
Receptors, Purinergic P1/*metabolism;
Receptors, Serotonin/*metabolism;
Spinal Cord/*metabolism;
Sulfones/*pharmacology;
Vasodilator Agents/therapeutic use
- From:Yonsei Medical Journal
2010;51(6):960-964
- CountryRepublic of Korea
- Language:English
-
Abstract:
PURPOSE: The phosphodiesterase 5 inhibitor sildenafil has antinociceptive effects, mediated by an increase in cGMP. This study examined the role of spinal adenosine and serotonin receptors played in the antinociceptive effects of intrathecal sildenafil. MATERIALS AND METHODS: Intrathecal catheters were inserted into the subarachnoid space of Sprague-Dawley male rats as a drug delivery device. Pain was induced by injecting formalin into the plantar surface of rats and observing nociceptive behavior (flinching response) for 60 mininutes. Then, the effects of intrathecal adenosine and serotonin receptor antagonists on the antinociceptive activity of intrathecal sildenafil were examined. RESULTS: Intrathecal sildenafil suppressed the flinching response in a dose-dependent manner during phases 1 and 2 in the formalin test. Both CGS 15943 and dihydroergocristine decreased the antinociceptive effects of sildenafil during phases 1 and 2 in the formalin test. CONCLUSION: Intrathecal sildenafil effectively attenuated the pain evoked by formalin injection. Both adenosine and serotonin receptors may be involved in the antinociceptive action of sildenafil at the spinal level.
