Evaluation for the Effects of Intrathecal Sildenafil on the Formalin- and Thermal-induced Nociception of Rats.
- Author:
Myung Ha YOON
1
;
Hong Buem BAE
;
Dong Jin SHIN
;
Chang Mo KIM
;
Sung Tae JEONG
;
Seok Jai KIM
;
Jeong Il CHOI
Author Information
- Publication Type:Original Article
- Keywords: antinociception; cyclic guanosine monophosphate; phosphodiesterase; sildenafil; spinal cord
- MeSH: Animals; Catheters; Cyclic Nucleotide Phosphodiesterases, Type 5; Formaldehyde; Guanosine Monophosphate; Hot Temperature; Nociception*; Pain Measurement; Rats*; Spinal Cord; Sildenafil Citrate
- From:The Korean Journal of Pain 2006;19(1):17-21
- CountryRepublic of Korea
- Language:Korean
- Abstract: BACKGROUND: Cyclic guanosine monophosphate (cGMP) plays an important role in the modulation of nociception. Although local sildenafil produces antinociception, by increasing cGMP through the inhibition of phosphodiesterase 5, the effect of spinal sildenafil has not been determined. The authors evaluated the effects of intrathecal sildenafil on the nociceptive behavior evoked by formalin injection and thermal stimulation. METHODS: Lumbar intrathecal catheters were implanted into rats, with formalin and Hot-Box tests used as nociceptive models. The formalin-induced nociceptive behavior (flinching response) and withdrawal latency to radiant heat were measured, and the general behaviors also observed. RESULTS: The intrathecal administration of sildenafil produced dose-dependent suppression of the flinches in both phases in the formalin test, and increased the withdrawal latency in the Hot-Box test. No abnormal behaviors were noted. CONCLUSIONS: Sildenafil, an inhibitor of phosphodiesterase 5, is active against the nociceptive state evoked in the spinal cord by formalin and thermal stimulations. Accordingly, spinal sildenafil may be useful in the management of pain.
