TY - JOUR
T1 - The inhibitory effect of locally injected dexmedetomidine on carrageenan-induced nociception in rats
AU - Honda, Yuka
AU - Higuchi, Hitoshi
AU - Matsuoka, Yoshikazu
AU - Yabuki-Kawase, Akiko
AU - Ishii-Maruhama, Minako
AU - Tomoyasu, Yumiko
AU - Maeda, Shigeru
AU - Morimatsu, Hiroshi
AU - Miyawaki, Takuya
PY - 2015/7/13
Y1 - 2015/7/13
N2 - Recent studies showed that the administration of dexmedetomidine relieved hyperalgesia in the presence of neuropathic pain. These findings have led to the hypothesis that the local administration of dexmedetomidine is useful for relieving acute inflammatory nociception, such as postoperative pain. Thus, we evaluated the inhibitory effect of locally injected dexmedetomidine on acute inflammatory nociception. Acute inflammatory nociception was induced by an intraplantar injection of 1% carrageenan into the hindpaws of rats, and dexmedetomidine was also injected combined with carrageenan. The paw withdrawal threshold based on von Frey filament stimulation was measured until 12 h after injection. We compared the area under the time-curve (AUC) between carrageenan and carrageenan with dexmedetomidine. To clarify that the action of dexmedetomidine was via α2-adrenoceptors, we evaluated the effect of yohimbine, a selective antagonist of α2-adrenoceptors, on the anti-nociception of dexmedetomidine. As the results, the intraplantar injection of carrageenan with over 10 μM dexmedetomidine significantly increased AUC, compared to that with only carrageenan injection. This effect of dexmedetomidine was reversed by the addition of yohimbine to carrageenan and dexmedetomidine. These results demonstrated that the locally injected dexmedetomidine was effective against carrageenan-induced inflammatory nociception via α2-adrenoceptors. The findings suggest that the local injection of dexmedetomidine is useful for relieving local acute inflammatory nociception.
AB - Recent studies showed that the administration of dexmedetomidine relieved hyperalgesia in the presence of neuropathic pain. These findings have led to the hypothesis that the local administration of dexmedetomidine is useful for relieving acute inflammatory nociception, such as postoperative pain. Thus, we evaluated the inhibitory effect of locally injected dexmedetomidine on acute inflammatory nociception. Acute inflammatory nociception was induced by an intraplantar injection of 1% carrageenan into the hindpaws of rats, and dexmedetomidine was also injected combined with carrageenan. The paw withdrawal threshold based on von Frey filament stimulation was measured until 12 h after injection. We compared the area under the time-curve (AUC) between carrageenan and carrageenan with dexmedetomidine. To clarify that the action of dexmedetomidine was via α2-adrenoceptors, we evaluated the effect of yohimbine, a selective antagonist of α2-adrenoceptors, on the anti-nociception of dexmedetomidine. As the results, the intraplantar injection of carrageenan with over 10 μM dexmedetomidine significantly increased AUC, compared to that with only carrageenan injection. This effect of dexmedetomidine was reversed by the addition of yohimbine to carrageenan and dexmedetomidine. These results demonstrated that the locally injected dexmedetomidine was effective against carrageenan-induced inflammatory nociception via α2-adrenoceptors. The findings suggest that the local injection of dexmedetomidine is useful for relieving local acute inflammatory nociception.
KW - Anti-nociception
KW - Dexmedetomidine
KW - Inflammatory pain
KW - Pain relief
KW - α<inf>2</inf>-Adrenoceptors
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UR - http://www.scopus.com/inward/citedby.url?scp=84937022148&partnerID=8YFLogxK
U2 - 10.1016/j.ejphar.2015.06.054
DO - 10.1016/j.ejphar.2015.06.054
M3 - Article
C2 - 26160316
AN - SCOPUS:84937022148
VL - 764
SP - 215
EP - 219
JO - European Journal of Pharmacology
JF - European Journal of Pharmacology
SN - 0014-2999
ER -