Pharmacological classification of adrenergic α receptors in the guinea pig

  title={Pharmacological classification of adrenergic $\alpha$ receptors in the guinea pig},
  author={Jarl E. S. Wikberg},
THE actions of sympathomimetic amines have attracted considerable attention for some time. Ahlquist1–3 introduced the concept of adrenergic α and β receptors to explain the differences in the effects of some of these amines on various organ systems and then Lands et al.4,5 suggested the existence of two types of β receptors, β1 and β2. It has been claimed that there is a pharmacological difference between α receptors at adrenergic neurones and those in smooth muscle6–9. I have previously shown… Expand
α-Adrenoceptors: Recent development and some comparative aspects
In the most advanced non-mammalian vertebrates (birds) both peripheral and central α-adrenoceptors seem to be qualitatively similar to the mammalian types, and in reptiles and amphibians α1- and α2-ad Renfrewshire receptors have been shown to exist. Expand
Regulation of the Postsynaptic α‐Adrenergic Receptor in Rat Mesenteric Artery: Effects of Chemical Sympathectomy and Epinephrine Treatment 1981
Vascular smooth muscle sensitivity to catecholamine-induced contraction is increased after catecholamine depletion by chemical sympathectomy and decreased after exogenous catecholα-mineExpand
Multiple Analgesic Receptors
ABSTRACT Neurophysiological observations support the hypothesis that morphine and benzomorphan analogs interact with several types of receptors (μ to morphine, K to Ketocyclazocine and σ toExpand
Subtype classification of presynaptic α2-adrenoceptors
A larger number of subtype-selective compounds may have to be characterized in the classification in the many tissues, where presynaptic α2-adrenoceptors are found. Expand
Pharmacological characterization of the alpha adrenoceptors of the dog basilar artery
The results indicate that presynaptic and postsynaptic alpha receptors of the dog basilar artery are largely alpha2 in contrast to those of peripheral arteries. Expand
β-adrenergic activity and conformation of the antihypertensive specific α2-agonist drug, guanabenz
Abstract In recent research a new series of specific drugs, one of which is guanabenz (GBZ, 2,6(di-chlorobenzyliden)-aminoguanidine)† has been introduced into the clinical treatment of centrallyExpand
Stereochemical requirements of a2-adrenergic receptors for a-methyl substituted phenethylamines
The α-carbon atom is a major determinant of the α 2 -adrenergic effects of phenethylamines, and plays an important role in determining α-receptor subtype specificity. Expand
Effects of antihypertensive clonidine congeners on alpha-adrenergic receptors.
There was a strong correlation between the antihypertensive doses of these congeners and their concentrations required to inhibit the binding of [3H]clonidine, compatible with the concept that the anti Hypertensive action of clonidine is more likely due to interactions withalpha-2 adrenergic receptors than with alpha-1 receptors. Expand
Pharmacology of B-HT 920 in some isolated smooth muscles of the guinea-pig.
It is suggested from the present results that B-HT 920 can induce inhibition of both cholinergic and adrenergic neurotransmission presumably by inducing selective stimulation of prejunctional alpha2-receptors. Expand
Biochemistry of alpha-2 Adrenergic Receptors
Physiologic and pharmacologic studies provide the present basis for the classification of alpha-adrenergic receptors and call for the existence of discrete alpha-1 and alpha-2 adrenergic receptors with the extant possibility of further subdivision among the alpha- 2 adrenergic receptor subtypes. Expand


A functional basis for classification of α-adrenergic receptors
A division of adrenergic receptors into alpha and beta types could conceivably lead to the development of powerful agents even more selective for inhibition of renin release, control of blood pressure by a central site of action, reduction of fever, and possible other scientific or therapeutic applications. Expand
A study of the adrenotropic receptors.
  • R. Ahlquist
  • Chemistry, Medicine
  • The American journal of physiology
  • 1948
Experiments described in this paper indicate that although there are two kinds of adrenotropic receptors they cannot be classified simply as excitatory or inhibitory since each kind of receptor may have either action depending upon where it is found. Expand
Pharmacological characterisation of the presynaptic α-adrenoceptor in the rat vas deferens
Abstract The interactions between α-adrenoceptors agonists and antagonists on the twitch response of the rat isolated vas deferens to low frequency motor nerve stimulation have been examined.Expand
Localization of adrenergic receptors in guinea pig ileum and rabbit jejunum to cholinergic neurons and to smooth muscle cells.
  • J. Wikberg
  • Chemistry, Medicine
  • Acta physiologica Scandinavica
  • 1977
It is suggested that in the guinea pig ileum alpha-adrenoceptors mediating relaxation are located only in cholinergic neurons, whereas in rabbit jejunum they are located both in these neurons and in the smooth muscle cells. Expand
Alpha adrenergic and histaminergic effects of tolazoline-like imidazolines.
It is concluded that oxymetazoline and naphazoline do not activate histamine 1 or histamine 2 receptors or beta adrenoceptors, and the drugs are highly specific alpha adrenoceptor stimulants. Expand
The effects of adrenaline, noradrenaline and isoprenaline on inhibitory α‐ and β‐adrenoceptors in the longitudinal muscle of the guinea‐pig ileum
1 Two preparations, a segment of the ileum and the myenteric plexus‐longitudinal muscle preparation, have been used for an analysis of the inhibitory effects of adrenaline, noradrenaline andExpand
Differentiation of Receptor Systems activated by Sympathomimetic Amines
Additional studies are reported which show that two distinct receptor types are at present included within this group of receptor types, and cannot be explained easily on the assumption that the β-type designates a single receptor population. Expand
Differentiation of receptors responsive to isoproterenol.
Structural modification of 1-(3,4-dihydroxyphenyl)-2-amino-ethanol, by adding a methyl or ethyl group at the carbon alpha to the nitrogen or by adding various alkyl groups in the nitrogen center, changes sympathomimetic activity, indicating that the β-receptor population can be divided into two distinct groups. Expand
Negative feedback regulation of noradrenaline release by nerve stimulation in the perfused cat's spleen: differences in potency of phenoxybenzamine in blocking the pre‐ and post‐synaptic adrenergic receptors
The effects of low concentrations of phenoxybenzamine on responses and on noradrenaline overflow elicited by nerve stimulation were studied in the perfused cat's spleen. Expand
Pharmacological estimation of drug-receptor dissociation constants. Statistical evaluation. I. Agonists.
  • R. B. Parker, D. Waud
  • Chemistry, Medicine
  • The Journal of pharmacology and experimental therapeutics
  • 1971
Objective statistical evaluation of the results of experiments designed to measure the dissociation constants of stimulant drugs is discussed, and a hyperbola is fitted directly to the data rather than by the conventional method of fitting a line to a reciprocal transformation of the data. Expand