title: Subtypes of adrenergic and dopaminergic receptors in bovine cerebral blood vessels.
abstract: Binding of the radiolabelled antagonists [3H]rauwolscine, [3H]SCH 23390 and (-)-[3H]dihydroalprenolol revealed the presence of alpha 2-adrenergic greater than DA1 dopaminergic greater than beta-adrenergic receptors in membrane preparations of calf basal cerebral arteries (basilar artery and circle of Willis) and pial vessels of the cerebral convexity. Computer-assisted analysis of ICI 118 551/(-)-[3H]dihydroalprenolol competition binding curves indicated the existence of beta 1- and beta 2-adrenergic receptor subtypes (beta 2/beta 1 ratio 7:3). No specific binding of [3H]prazosin (to alpha 1-adrenergic receptors) and [3H]spiroperidol (to DA2 dopaminergic receptors) was detected. Whereas DA1, beta 1- and beta 2-receptor densities were very similar in both blood vessel types, the alpha 2-receptor density was 3-fold higher in the pial vessels of the convexity. This suggests a functionally more important vasoconstrictor adrenergic control of the cerebral circulation in pial vessels of the convexity than in the arteries at the base of the brain.
authors.affiliation: Department of Neurology, Akademisch Ziekenhuis, Vrije Universiteit Brussel, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: De Keyser
authors.forename: G
authors.initials: G
authors.lastname: Ebinger
authors.forename: J P
authors.initials: JP
authors.lastname: De Backer
authors.forename: A
authors.initials: A
authors.lastname: Convents
authors.forename: P
authors.initials: P
authors.lastname: Vanderheyden
authors.forename: G
authors.initials: G
authors.lastname: Vauquelin
mesh_terms: D000818:Animals; D001552:Benzazepines / Q000378:metabolism; D002417:Cattle; D002536:Cerebral Arteries / Q000032:analysis*; D004082:Dihydroalprenolol / Q000378:metabolism; D011869:Radioligand Assay; D011942:Receptors, Adrenergic, alpha / Q000032:analysis* / Q000145:classification; D011943:Receptors, Adrenergic, beta / Q000032:analysis* / Q000145:classification; D011954:Receptors, Dopamine / Q000032:analysis* / Q000145:classification; D013134:Spiperone / Q000378:metabolism; D015016:Yohimbine / Q000378:metabolism
chemical_list: D001552:Benzazepines; D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D011954:Receptors, Dopamine; D015016:Yohimbine; D013134:Spiperone; D004082:Dihydroalprenolol