A. Capasso et al., RECEPTOR-MEDIATED INHIBITION OF OCTOPAMINE-STIMULATED ADENYLATE-CYCLASE IN THE OPTIC LOBE OF OCTOPUS-VULGARIS, Comparative biochemistry and physiology. C. Comparative pharmacologyand toxicology, 106(2), 1993, pp. 555-559
1. Inhibition of octopamine-stimulated adenylate cyclase was studied i
n the optic lobe of Octopus vulgaris. 2. The octopamine antagonist, mi
anserin, and the dopamine D2 agonists, PPHT and metergoline, induced d
ose-dependent inhibition of octopamine-stimulated adenylate cyclase ac
tivity. 3. The binding of the tritiated benzazepine neuroleptic YM-091
51-2 to octopus membranes and the displacement of [H-3]YM-09151-2 by P
PHT, metergoline and spiperone were consistent with the presence of a
D2-like dopamine receptor in the octopus optic lobe. 4. The conclusion
is drawn that octopamine-stimulated adenylate cyclase in the octopus
is negatively regulated by a dopamine D2-like receptor.