Antinociceptive effect of buprenorphine in mu sub(1)-opioid receptor deficient CXBK mice

• Published in: Life sciences (1973) 1997-04, Vol.60 (22), p.PL333-PL337
• Main Authors: Kamei, J, Sodeyama, M, Tsuda, M, Suzuki, T, Nagase, H
• Format: Article
• Language: English
• ISSN: 0024-3205

The antinociceptive effect of buprenorphine was examined in mu sub(1)-opioid receptor-deficient CXBK mice. I.p. administration of buprenorphine at a dose of 3 mg/kg produced marked antinociception in the tail-flick test in C57BL/6 mice, a progenitor strain of CXBK mice. The antinociceptive effect of buprenorphine in C57BL/6 mice was antagonized by pretreatment with either beta -funaltrexamine ( beta -FNA), a mu -opioid receptor antagonist, or naloxonazine (NXZ), a selective mu sub(1)-opioid receptor antagonist. The antinociceptive effect of buprenorphine (3 mg/kg, i.p.) in CXBK mice was significantly less than that in C57BL/6 mice. Neither beta -FNA nor NXZ reduced the antinociceptive effect of buprenorphine in CXBK mice. There was no significant difference between the buprenorphine-induced antinociceptive effect in CXBK mice and NXZ-treated C57BL/6 mice. Furthermore, neither naltrindole, a selective delta -opioid receptor antagonist, nor norbinaltorphimine, a selective Kappa -opioid receptor antagonist, had a significant effect on the antinociceptive effects of buprenorphine in both CXBK and C57BL/6 mice. These results support our previous hypothesis that mu sub(1)- rather than mu sub(2)-, delta - or Kappa -opioid receptors are involved in the antinociceptive effects of buprenorphine.