PMID: 6108815Dec 1, 1980Paper

Presence of postsynaptic alpha 2-adrenoreceptors of predominantly extrasynaptic location in the vascular smooth muscle of the dog hind limb

Clinical Science
S Z LangerN B Shepperson

Abstract

1. In the autoperfused hind limb of the dog prazosin (10 microgram/kg intravenously) markedly antagonized responses to lumbar sympathetic stimulation, whereas responses to injected noradrenaline were largely unaffected. 2. In beta-adrenoreceptor- and ganglion-blocked animals, the hind limb pressor responses to phenylephrine were antagonized to a greater degree by prazosin than responses to injected noradrenaline. 3. Rauwolscine, a selective alpha 2-adrenoreceptor-blocking agent, antagonized responses to the alpha 2-adrenoreceptor agonist guanabenz, but not those to phenylephrine. 4. Hind limb pressor responses to noradrenaline were significantly inhibited by rauwolscine and further reduced by prazosin. 5. These results demonstrate that in this vascular bed alpha 1- and alpha 2-adrenoreceptors are located postsynaptically. Furthermore the results suggest that neuronally released noradrenaline acts mainly upon alpha 1-adrenoreceptors, whereas exogenous noradrenaline acts upon alpha 1- and alpha 2-adrenoreceptors. 6. It is suggested that this selectivity of prazosin in blocking the vasoconstriction to neuronally-released noradrenaline may in part explain the effectiveness of this drug as an antihypertensive agent.

Citations

Sep 1, 1983·Journal of Autonomic Pharmacology·P E Hicks
Jun 1, 1983·Journal of Autonomic Pharmacology·P E Hicks
Nov 1, 1982·The British Journal of Dermatology·S Z Langer, C Pimoule
May 15, 1983·Biochemical Pharmacology·E J Ariëns, A M Simonis
Feb 1, 1982·Naunyn-Schmiedeberg's Archives of Pharmacology·P T HornL I Goldberg
Feb 1, 1993·Annals of Emergency Medicine·J P Ornato
Sep 1, 1991·Clinical Autonomic Research : Official Journal of the Clinical Autonomic Research Society·M LiguerosM Wilkins
Sep 1, 1985·Journal of Cerebral Blood Flow and Metabolism : Official Journal of the International Society of Cerebral Blood Flow and Metabolism·G Ferrari-DiLeo, L T Potter
Oct 1, 1987·Naunyn-Schmiedeberg's Archives of Pharmacology·R R RuffoloJ P Hieble
Sep 1, 1983·Naunyn-Schmiedeberg's Archives of Pharmacology·T TsukaharaH Handa
Apr 1, 1984·Naunyn-Schmiedeberg's Archives of Pharmacology·I J KopinD S Goldstein
Dec 1, 1981·Naunyn-Schmiedeberg's Archives of Pharmacology·N B Shepperson, S Z Langer
Jul 1, 1984·Naunyn-Schmiedeberg's Archives of Pharmacology·R R RuffoloJ S Horng
Jul 1, 1983·Naunyn-Schmiedeberg's Archives of Pharmacology·R R RuffoloD D Miller
Dec 1, 1986·Naunyn-Schmiedeberg's Archives of Pharmacology·T TsukaharaH Handa
Apr 1, 1982·Naunyn-Schmiedeberg's Archives of Pharmacology·Y SakakibaraI Muramatsu
Jan 1, 1985·Stroke; a Journal of Cerebral Circulation·T TsukaharaM Nishikawa
Jun 1, 1986·Hypertension·D S GoldsteinI J Kopin
Jan 1, 1989·Clinical and Experimental Pharmacology & Physiology. Supplement·H HosomiH Morita
Apr 1, 1989·Cardiovascular Drugs and Therapy·P A van Zwieten
Apr 1, 1984·Naunyn-Schmiedeberg's Archives of Pharmacology·R A MaciaR M DeMarinis
Feb 1, 1983·Naunyn-Schmiedeberg's Archives of Pharmacology·M Gerold, G Haeusler

❮ Previous
Next ❯

Related Concepts

Related Feeds

Adrenergic Receptors: Trafficking

Adrenergic receptor trafficking is an active physiological process where adrenergic receptors are relocated from one region of the cell to another or from one type of cell to another. Discover the latest research on adrenergic receptor trafficking here.