title: D2-dopamine receptors regulate the release of [3H]dopamine in rat basal hypothalamus and neurointermediate lobe of the pituitary gland.
abstract: Homogenates of the rat basal hypothalamus and the neurointermediate lobe of the pituitary gland contained relatively high levels of dopamine as was estimated by high-performance liquid chromatography (HPLC). The release of [3H]dopamine was studied in these regions and desipramine was used to prevent uptake of [3H]dopamine in noradrenergic nerve terminals. The release of radioactivity could be stimulated electrically and was calcium-dependent. It appeared that the release of radioactivity could be inhibited by drugs stimulating D2-dopamine receptors in both regions. The radioactivity released during electrical stimulation was analysed by cation exchange chromatography and appeared to consist predominantly of [3H]dopamine. It is our conclusion that D2-receptors mediate the inhibition of the release of [3H]dopamine from dopaminergic nerve terminals in the basal hypothalamus and in the neurointermediate lobe.
mesh_terms: D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D004298:Dopamine / Q000378:metabolism*; D004558:Electric Stimulation; D004873:Ergolines / Q000494:pharmacology; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009638:Norepinephrine / Q000378:metabolism; D010902:Pituitary Gland / Q000187:drug effects / Q000378:metabolism*; D019257:Quinpirole; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects / Q000502:physiology*; D017448:Receptors, Dopamine D2; D013469:Sulpiride / Q000494:pharmacology; D013764:Tetrahydronaphthalenes / Q000494:pharmacology; D013876:Thiophenes / Q000494:pharmacology
chemical_list: D001552:Benzazepines; D004873:Ergolines; D011954:Receptors, Dopamine; D017448:Receptors, Dopamine D2; D013764:Tetrahydronaphthalenes; D013876:Thiophenes; D019257:Quinpirole; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D013469:Sulpiride; C047508:rotigotine; D002118:Calcium; D004298:Dopamine; D009638:Norepinephrine