title: Retina contains guanine nucleotide sensitive and insensitive classes of dopamine receptors.
abstract: Calf retina contains high affinity, stereospecific and saturable binding sites, characterized as dopaminergic, for 3H-spiropheridol (Bmax from Scatchard analysis = 38 +/- 4 fmoles/mg protein) and for 3H-ADTN (2-amino-6,7-dihydroxy-1,2,3,4-tetrahydronaphthalene). The 3H-ADTN sites include a discrete and saturable sub-set of sites sensitive to guanine nucleotide inhibition (Bmax = 50 +/- 6 fmoles/mg protein) and a separate saturable sub-set of sites insensitive to guanine nucleotides (Bmax = 63 +/- 7 fmoles/mg protein). The binding of agonists to 3H-spiroperidol sites is also inhibited by guanine nucleotides.
mesh_terms: D000262:Adenylyl Cyclases / Q000032:analysis; D000818:Animals; D001058:Apomorphine / Q000378:metabolism; D001665:Binding Sites; D002069:Butaclamol / Q000494:pharmacology; D002417:Cattle; D003342:Corpus Striatum / Q000032:analysis; D006150:Guanine Nucleotides / Q000494:pharmacology*; D006160:Guanosine Triphosphate / Q000494:pharmacology; D007700:Kinetics; D009284:Naphthols / Q000378:metabolism; D051381:Rats; D011954:Receptors, Dopamine / Q000032:analysis* / Q000187:drug effects; D012160:Retina / Q000032:analysis*; D013134:Spiperone / Q000378:metabolism; D013764:Tetrahydronaphthalenes
chemical_list: D006150:Guanine Nucleotides; D009284:Naphthols; D011954:Receptors, Dopamine; D013764:Tetrahydronaphthalenes; D013134:Spiperone; C011639:ADTN; D006160:Guanosine Triphosphate; D002069:Butaclamol; D000262:Adenylyl Cyclases; D001058:Apomorphine