Opioid inhibition of dopamine release from nervous tissue of Mytilus edulis and Octopus bimaculatus

Science  21 Aug 1981:
Vol. 213, Issue 4510, pp. 928-930
DOI: 10.1126/science.6266017


Morphine and D-Ala2-Met-enkephalin as well as other opioids suppress potassium-stimulated release of 3H-labeled dopamine from neurons tissue of two marine invertebrates, Mytilus edulis and Octopus bimaculatus. Naloxone reverses the inhibitory effects in both species. Potassium-stimulated release of 3H-labeled serotonin is not altered by opioids. It is postulated that opiate receptors and their endogenous effectors play a prominent role in regulation of transmitter release in invertebrates.