title: Adrenoceptor profile of blood vessels in the knee joint of the rabbit.
abstract: 1. An in vitro preparation of the rabbit knee joint, perfused with oxygenated Locke solution, was used to assess the nature of adrenoceptors within articular blood vessels. 2. Dose/response relationships were obtained to intra-arterial injection of alpha- and beta-adrenoceptor agonists. 3. Adrenaline and noradrenaline produced a similar pattern of increasing constriction of articular vessels with increasing dose of drug. 4. The alpha 1-agonist, phenylephrine, also produced dose-dependent constrictor responses, but the alpha 2-agonist; clonidine, had no effect. The alpha 2-agonist UK-14304 did, however, produce modest vasoconstriction which was not greatly altered by the alpha 1-blocker prazosin. The constrictor effect of noradrenaline was abolished by both the alpha 1,2-blocker phenoxybenzamine and by prazosin but not by the alpha 2-blocker rauwalscine. 5. The beta-adrenoceptor agonist, isoprenaline, had little effect at a dose of 10(-6) M or lower, but gave rise to a constrictor effect at higher concentrations. This response was blocked by phenoxybenzamine but not by the beta 1,2-blocker propranolol, suggesting that the constrictor effect was mediated via alpha-adrenoceptors. 6. The results suggest that alpha 1- and alpha 2-adrenoceptors are present within articular blood vessels, but that beta-receptors are absent. The effects of noradrenaline appear to be mediated principally via alpha 1-adrenoceptors.
authors.affiliation: Institute of Physiology, University of Glasgow.
authors.forename: W R
authors.initials: WR
authors.lastname: Ferrell
authors.forename: A
authors.initials: A
authors.lastname: Khoshbaten
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001808:Blood Vessels / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004837:Epinephrine / Q000494:pharmacology; D007719:Knee Joint / Q000098:blood supply*; D009638:Norepinephrine / Q000494:pharmacology; D011817:Rabbits; D011941:Receptors, Adrenergic / Q000378:metabolism*; D011942:Receptors, Adrenergic, alpha / Q000378:metabolism; D011943:Receptors, Adrenergic, beta / Q000378:metabolism; D014661:Vasoconstriction
chemical_list: D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D011941:Receptors, Adrenergic; D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D009638:Norepinephrine; D004837:Epinephrine