Calcitonin increases the inhibitory effect of opioids in guinea-pig ileum.
1. The relationship between salmon calcitonin (S-CT) and opioid system was studied in isolated guinea-pig ileum. 2. Addition of S-CT (0.1 to 1.6 U/ml) to the organ bath did not modify the amplitude of the contractile response induces by electrical stimulation. 3. However, when tissues were incubated 30 min with S-CT (0.1 U/ml), the inhibitory effect of the release of endogenous opioids, met-enkephalin (1 microM) and morphine (0.2 microM) was significantly increased. 4. Our results suggest that some of the analgesic effects of S-CT could be attributed to an up-regulation of the opioid receptors.
Martin
M I
MI
Departamento de Farmacología, Facultad de Medicina, Universidad Complutense, Madrid, Spain.
Colado
M I
MI
Alfaro
M J
MJ
D000818:Animals; D001575:Benzomorphans / Q000494:pharmacology; D002116:Calcitonin / Q000494:pharmacology*; D004558:Electric Stimulation; D004744:Enkephalin, Methionine / Q000494:pharmacology; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009020:Morphine / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D009197:Myenteric Plexus / Q000187:drug effects; D009270:Naloxone / Q000494:pharmacology; D009294:Narcotics / Q000494:pharmacology*
D001575:Benzomorphans; D009294:Narcotics; D009270:Naloxone; C027247:MR 2266; D004744:Enkephalin, Methionine; D009020:Morphine; C028815:salmon calcitonin; D002116:Calcitonin