%0 Journal Article %T Interleukin-2-induced antinociception in morphine-insensitive rats. %A SONG Ping %A LIU Xin-Yuan %A ZHAO Zhi-Qi %J Acta Pharmacologica Sinica %D 2016 %B 2016 %9 %! Interleukin-2-induced antinociception in morphine-insensitive rats. %K %X AIM: To investigate interleukin-2-induced antinociception in morphine-insensitive rats. METHODS: Paw withdrawal latencies (PWL) to noxious radiant heat were taken as the measurement of pain threshold. RESULTS: Intraplantar injection of human recombinant interleukin-2 (1.5 x10(4) U) significantly increased PWL in normal rats. PWL was also markedly increased by IL-2 in 45-d-post-complete Freund's adjuvant (CFA)-treated rats, which have been proven morphine-insensitive. IL-2-induced antinociception in CFA-treated rats were significantly lower than that in normal rats. IL-2-induced antinociception was partially blocked by naloxone (1 mg/kg, ip) in normal rats but remained unchanged in CFA group. CONCLUSION: IL-2-induced antinociception is partially mediated by mu-opioid receptors. Therapeutic applications of IL-2 may also be expanded to relieve morphine-insensitive pain. %U http://www.chinaphar.com/article/view/7201 %V 23 %N 11 %P 981-984 %@ 1745-7254