The effects of dopamine agonists and antagonists on the secretory responses in the salivary glands of the locust (Locusta migratoria).
A study has been made on the effect of dopamine on salivary gland secretion rates from isolated locust salivary glands. Application of dopamine induced a concentration-dependent secretion with an IC(50) of approximately 0.3 microM. We investigated the pharmacological profile of this receptor using dopaminergic agonists and antagonists. The effects of dopamine could be mimicked by the selective D1 agonist SKF82958, but not by the D2 agonist TNPA-HCl. The receptor also showed selectively towards certain D1 agonists. SKF82958 was more potent at inducing secretion than SKF81297. We found that dopamine-induced salivary secretions were blocked by the selective D1 antagonist SCH23390, whereas the D2 antagonist sulpiride was relatively ineffective. The cAMP analogue 8-Bromo cAMP also increased secretion rates from isolated salivary glands. These data and the rank order of potency of the agonists and antagonists in this screen suggest that this receptor is a D1-type receptor.
Keating
Christopher
C
Department of Zoology, University of Toronto, 25 Harbord Street, Toronto, Ontario M5S 3G5, Canada. c.d.keating@sussex.ac.uk
Orchard
Ian
I
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D001060:Aporphines / Q000494:pharmacology; D001552:Benzazepines / Q000494:pharmacology; D002352:Carrier Proteins / Q000502:physiology; D004298:Dopamine / Q000502:physiology; D018491:Dopamine Agonists / Q000494:pharmacology*; D018492:Dopamine Antagonists / Q000494:pharmacology*; D006110:Grasshoppers / Q000502:physiology*; D009924:Organ Culture Techniques; D017447:Receptors, Dopamine D1 / Q000187:drug effects; D012463:Saliva / Q000378:metabolism*; D012469:Salivary Glands / Q000187:drug effects / Q000378:metabolism*; D050486:Serotonin Plasma Membrane Transport Proteins; D013469:Sulpiride / Q000494:pharmacology
D001060:Aporphines; D001552:Benzazepines; D002352:Carrier Proteins; D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D017447:Receptors, Dopamine D1; D050486:Serotonin Plasma Membrane Transport Proteins; D015124:8-Bromo Cyclic Adenosine Monophosphate; C067113:SK&F 81297; C031796:2,10,11-trihydroxy-N-n-propylnoraporphine; D013469:Sulpiride; C071262:SK&F 82958; D004298:Dopamine