ANALGESIC EFFECT OF 2 CALCITONINS AND IN-VITRO INTERACTION WITH OPIOIDS

1. When the analgesic effect of salmon-calcitonin (S-CT) and of eel-ca lcitonin (E-CT), as well as their influence on the morphine-analgesia were compared, no significant differences were found. 2. While on isol ated tissues, E-CT induced a significant increase on the effect of bre mazocine, [D-Pen(2),D-Pen(5)]enkephalin and [Met(5)]enkephalin and no changes were observed on the effect of DAMGO, suggesting that E-CT inc reases the effects of opioids acting on delta or kappa receptors but n ot on mu receptors. 3. These findings corroborate the possibility of i nteractions between calcitonin and the opioid system.