Monoamine activation and enkephalin inhibition of adenylate cyclase in dorsal and ventral striatum of the rabbit.
Adrenergic-sensitive adenylate cyclase was found to be present in the nucleus accumbens and ventral caudate of the rabbit, but displayed less activity in the dorsal caudate. In general, stimulation of the enzyme by dopamine (DA) was most sensitive to inhibition by fluphenazine while norepinephrine (NE)-stimulated activity was highly sensitive to both fluphenazine and propranolol. Other selective adrenergic-receptor blocking agents (butoxamine, practolol, yohimbine and prazosine) were more effective in antagonizing the effect of NE as opposed to DA-activation. Activation of adenylate cyclase by NE in the dorsal caudate displayed less sensitivity to these adrenergic antagonists than in the other two areas. Horseradish peroxidase-positive cells were present in the locus coeruleus, following injection into the nucleus accumbens. Activity of basal and guanosine triphosphate (GTP)-sensitive adenylate cyclase was reduced by enkephalins in these three brain regions. This action was reversed by naloxone. Met-enkephalin did not affect either NE- or DA-mediated responses in any area.
D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D002421:Caudate Nucleus / Q000187:drug effects; D003342:Corpus Striatum / Q000187:drug effects* / Q000201:enzymology; D004298:Dopamine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004744:Enkephalin, Methionine / Q000494:pharmacology*; D005476:Fluphenazine / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000494:pharmacology; D008125:Locus Coeruleus / Q000187:drug effects; D009474:Neurons / Q000187:drug effects; D009638:Norepinephrine / Q000494:pharmacology*; D009714:Nucleus Accumbens / Q000187:drug effects; D011433:Propranolol / Q000494:pharmacology; D011817:Rabbits; D013268:Stimulation, Chemical
D000067956:Adenylyl Cyclase Inhibitors; D004744:Enkephalin, Methionine; D006160:Guanosine Triphosphate; D011433:Propranolol; D000262:Adenylyl Cyclases; D005476:Fluphenazine; D004298:Dopamine; D009638:Norepinephrine