The antinociceptive effects of intravenous dexmedetomidine in colorectal distension-induced visceral pain in rats: The role of opioid receptors
[ X ]
Tarih
2009
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Lippincott Williams and Wilkins
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
BACKGROUND: In comparison with cutaneous pain, the role of ?2-adrenoceptor (?2-AR) agonists in visceral pain has not been extensively examined. We aimed to characterize the antinociceptive effect of IV dexmedetomidine on visceral pain in rats and to determine whether antinociception thus produced is mediated by opioid receptors. METHODS: Male Sprague Dawley rats (250-300 g) were instrumented with a venous catheter for drug administration and with enameled nichrome electrodes for electromyography of the external oblique muscles. Colorectal distension (CRD) was used as the noxious visceral stimulus, and the visceromotor response to CRD was quantified electromyographically before and 5, 15, 30, 60, 90, and 120 min after dexmedetomidine or clonidine administration. Antagonists were administered 10 min before dexmedetomidine. After confirmation of normal distribution of data, one-way analysis of variance with the Tukey-Kramer post hoc test was used for multiple comparison. RESULTS: IV administration of dexmedetomidine (2.5-20 ?g/kg) and clonidine (10-80 ?g/kg) produced a dose-dependent reduction in visceromotor response with 50% effective dose values of 10.5 and 37.6 ?g/kg, respectively. Administration of the nonspecific ?2-AR antagonist yohimbine (1 mg/kg), but not the peripherally restricted ?2-AR antagonist MK-467 (1 mg/kg), abolished the antinociceptive effect of dexmedetomidine (10 ?g/kg). In addition, inhibition of opioid receptors by naloxone (1 mg/kg) attenuated the antinociceptive effect of dexmedetomidine. CONCLUSION: Our data indicate that IV dexmedetomidine exerts pronounced antinociception against CRD-induced visceral pain and suggest that the antinociceptive effect of dexmedotimidine is mediated in part by opioid receptors, but peripheral ?2-ARs are not involved. Copyright © 2009 International Anesthesia Research Society.
Açıklama
Anahtar Kelimeler
[Belirlenecek]
Kaynak
Anesthesia and Analgesia
WoS Q Değeri
N/A
Scopus Q Değeri
Q1
Cilt
109
Sayı
2
Künye
Ülger, F., Bozkurt, A., Bilge, S. S., Ilkaya, F., Dilek, A. N., Bostancı, M .Ö., Çiftcioğlu, E., Güldoğuş, F. (2009). The antinociceptive effects of intravenous dexmedetomidine in colorectal distension-induced visceral pain in rats: the role of opioid receptors. Anesthesia and analgesia, 109 (2), 616-622 .
