title: Subtypes of beta-adrenergic receptors in rat cerebral microvessels.
abstract: The 125I-labeled iodohydroxybenzylpindolol (IHYP) binding to beta-receptors on brain micro-vessels is inhibited by isoproterenol, epinephrine and norepinephrine, with Ki values of 2 X 10(-7) M, 2.5 X 10(-6) M and 1.2 X 10(-5) M, respectively. A modified Scatchard analysis of the inhibitory effects of practolol, metroprolol and zinterol on IHYP binding has shown that the proportion of beta 2-receptors in our preparation is about 80% of the total beta-adrenergic receptor population. Our data indicate that the beta-adrenergic receptors located on cerebral microvessels are of both beta 1 and beta 2 types, with a predominance of the beta 2 type.
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D002560:Cerebrovascular Circulation; D004983:Ethanolamines / Q000494:pharmacology; D007700:Kinetics; D008790:Metoprolol / Q000494:pharmacology; D010869:Pindolol / Q000031:analogs & derivatives / Q000378:metabolism; D011217:Practolol / Q000494:pharmacology; D051381:Rats; D011941:Receptors, Adrenergic / Q000378:metabolism*; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000378:metabolism*
chemical_list: D004983:Ethanolamines; D011941:Receptors, Adrenergic; D011943:Receptors, Adrenergic, beta; C011878:iodohydroxybenzylpindolol; C002904:zinterol; D010869:Pindolol; D008790:Metoprolol; D011217:Practolol