Influence of salmon calcitonin on the analgesic effect of selective kappa-opioid agonist in mice.

In the present study the relationship between calcitonin and kappa-opioid system was analysed. The possibility that salmon calcitonin (S-CT) exerts analgesic activity in mice as well as the influence of salmon calcitonin on the analgesic effect of kappa-opioid agonist, U-50, 488H were examined. The writhing test in mice was used as analgesic test. S-CT given alone intraperitoneally at a high dose produced antinociceptive effect. S-CT given at a subanalgesic dose increased the antinociceptive effect of kappa-opioid agonist, U-50, 488H. The obtained results suggest that the increase in the effectiveness of kappa-opioid receptor agonist may be one of the mechanisms involved in the analgesia induced by salmon calcitonin.